[ci skip] Using sanitize=true for GitHub hosted SVGs.

H/T to https://stackoverflow.com/a/16462143/1068170

I made sure the templates are populated correctly via:

$ python scripts/doc_template_release.py
CircleCI Build ID: 1405
AppVeyor Build ID: 1.0.1078.master
Coveralls Build ID: 19821542
Travis Build ID: 448688540

README.rst

@@ -166,13 +166,13 @@ details, see `the LICENSE`_.
 .. |docs| image:: https://readthedocs.org/projects/bezier/badge/?version=0.9.0
    :target: https://bezier.readthedocs.io/en/0.9.0/
    :alt: Documentation Status
-.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/circleci-passing.svg
+.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/circleci-passing.svg?sanitize=true
    :target: https://circleci.com/gh/dhermes/bezier/1405
    :alt: CircleCI Build
-.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/travis-passing.svg
+.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/travis-passing.svg?sanitize=true
    :target: https://travis-ci.org/dhermes/bezier/builds/448688540
    :alt: Travis Build
-.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/appveyor-passing.svg
+.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/appveyor-passing.svg?sanitize=true
    :target: https://ci.appveyor.com/project/dhermes/bezier/build/1.0.1078.master
    :alt: AppVeyor CI Build
 .. |coverage| image:: https://s3.amazonaws.com/assets.coveralls.io/badges/coveralls_100.svg

README.rst.release.template

@@ -166,13 +166,13 @@ details, see `the LICENSE`_.
 .. |docs| image:: https://readthedocs.org/projects/bezier/badge/?version={version}
    :target: https://bezier.readthedocs.io/en/{version}/
    :alt: Documentation Status
-.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/circleci-passing.svg
+.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/circleci-passing.svg?sanitize=true
    :target: https://circleci.com/gh/dhermes/bezier/{circleci_build}
    :alt: CircleCI Build
-.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/travis-passing.svg
+.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/travis-passing.svg?sanitize=true
    :target: https://travis-ci.org/dhermes/bezier/builds/{travis_build}
    :alt: Travis Build
-.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/appveyor-passing.svg
+.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/appveyor-passing.svg?sanitize=true
    :target: https://ci.appveyor.com/project/dhermes/bezier/build/{appveyor_build}
    :alt: AppVeyor CI Build
 .. |coverage| image:: https://s3.amazonaws.com/assets.coveralls.io/badges/coveralls_100.svg

docs/index.rst

@@ -216,13 +216,13 @@ details, see `the LICENSE`_.
 
 .. _the LICENSE: https://github.com/dhermes/bezier/blob/0.9.0/LICENSE
 
-.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/circleci-passing.svg
+.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/circleci-passing.svg?sanitize=true
    :target: https://circleci.com/gh/dhermes/bezier/1405
    :alt: CircleCI Build
-.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/travis-passing.svg
+.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/travis-passing.svg?sanitize=true
    :target: https://travis-ci.org/dhermes/bezier/builds/448688540
    :alt: Travis Build
-.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/appveyor-passing.svg
+.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/0.9.0/docs/appveyor-passing.svg?sanitize=true
    :target: https://ci.appveyor.com/project/dhermes/bezier/build/1.0.1078.master
    :alt: AppVeyor CI Build
 .. |coverage| image:: https://s3.amazonaws.com/assets.coveralls.io/badges/coveralls_100.svg

docs/index.rst.release.template

@@ -216,13 +216,13 @@ details, see `the LICENSE`_.
 
 .. _the LICENSE: https://github.com/dhermes/bezier/blob/{version}/LICENSE
 
-.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/circleci-passing.svg
+.. |circle-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/circleci-passing.svg?sanitize=true
    :target: https://circleci.com/gh/dhermes/bezier/{circleci_build}
    :alt: CircleCI Build
-.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/travis-passing.svg
+.. |travis-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/travis-passing.svg?sanitize=true
    :target: https://travis-ci.org/dhermes/bezier/builds/{travis_build}
    :alt: Travis Build
-.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/appveyor-passing.svg
+.. |appveyor-build| image:: https://raw.githubusercontent.com/dhermes/bezier/{version}/docs/appveyor-passing.svg?sanitize=true
    :target: https://ci.appveyor.com/project/dhermes/bezier/build/{appveyor_build}
    :alt: AppVeyor CI Build
 .. |coverage| image:: https://s3.amazonaws.com/assets.coveralls.io/badges/coveralls_100.svg

scripts/check_doc_templates.py

@@ -156,23 +156,23 @@
 )
 CIRCLECI_BADGE_RELEASE = (
     "https://raw.githubusercontent.com/dhermes/bezier/{version}/"
-    "docs/circleci-passing.svg"
+    "docs/circleci-passing.svg?sanitize=true"
 )
 TRAVIS_BADGE = (
     "https://img.shields.io/travis/dhermes/bezier/master.svg?"
     "maxAge=3600&label=Mac%20OS%20X"
 )
 TRAVIS_BADGE_RELEASE = (
     "https://raw.githubusercontent.com/dhermes/bezier/{version}/"
-    "docs/travis-passing.svg"
+    "docs/travis-passing.svg?sanitize=true"
 )
 APPVEYOR_BADGE = (
     "https://img.shields.io/appveyor/ci/dhermes/bezier/master.svg?"
     "maxAge=3600&label=Windows"
 )
 APPVEYOR_BADGE_RELEASE = (
     "https://raw.githubusercontent.com/dhermes/bezier/{version}/"
-    "docs/appveyor-passing.svg"
+    "docs/appveyor-passing.svg?sanitize=true"
 )
 COVERALLS_BADGE = "https://coveralls.io/repos/github/dhermes/bezier/badge.svg"
 COVERALLS_BADGE_RELEASE = (