Test dev package on Python 3 (#1956)

.travis.yml

@@ -39,10 +39,10 @@ jobs:
   include:
     - stage: test_changed
       script:
-       - ddev dep verify
-       - ddev manifest verify --include-extras
-       - ddev test
-       - ddev test --bench || true
+        - ddev dep verify
+        - ddev manifest verify --include-extras
+        - ddev test
+        - ddev test --bench || true
     - stage: test
       env: CHECK=datadog_checks_base
       script:
@@ -51,7 +51,7 @@ jobs:
         - travis_retry ddev test ${CHECK}
         - ddev test ${CHECK} --bench || true
     - stage: test
-      env: CHECK=datadog_checks_dev
+      env: CHECK=datadog_checks_dev PYTHON3=true
     - stage: test
       env: CHECK=active_directory
     - stage: test
@@ -193,6 +193,7 @@ jobs:
 before_install:
   - chmod +x .travis/prepare.sh
   - .travis/prepare.sh
+  - PATH="$PATH:$(pyenv root)/versions/3.6/bin"
 install:
   - pip install -U pip setuptools
   - pip install ./datadog_checks_dev[cli]

datadog_checks_dev/tox.ini

@@ -1,8 +1,9 @@
 [tox]
 minversion = 2.0
+skip_missing_interpreters = true
 basepython = py27
 envlist =
-    dev
+    {py27,py36}-dev
     flake8
 
 [testenv]
@@ -11,14 +12,10 @@ platform = linux|darwin|win32
 deps =
     ../datadog_checks_base
     -r../datadog_checks_base/requirements.in
+    -rrequirements-dev.txt
 passenv =
     DOCKER*
     COMPOSE*
-
-[testenv:dev]
-deps =
-    {[testenv]deps}
-    -rrequirements-dev.txt
 commands =
     pytest -v