fix: require python 3.7+

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:a5d81b61dfd1a432d3c03f51a25d2e71b37be24da509966d50724aea7c57c5c2
-# created: 2022-07-04T12:33:08.125873124Z
+  digest: sha256:e7bb19d47c13839fe8c147e50e02e8b6cf5da8edd1af8b82208cd6f66cc2829c
+# created: 2022-07-05T18:31:20.838186805Z

.repo-metadata.json

@@ -13,5 +13,6 @@
     "requires_billing": true,
     "default_version": "v1",
     "codeowner_team": "@googleapis/api-spanner-python",
-    "api_shortname": "spanner"
+    "api_shortname": "spanner",
+    "api_description": "is a fully managed, mission-critical, \nrelational database service that offers transactional consistency at global scale, \nschemas, SQL (ANSI 2011 with extensions), and automatic, synchronous replication \nfor high availability.\n\nBe sure to activate the Cloud Spanner API on the Developer's Console to\nuse Cloud Spanner from your project."
 }

CONTRIBUTING.rst

@@ -22,7 +22,7 @@ In order to add a feature:
   documentation.
 
 - The feature must work fully on the following CPython versions:
-  3.6, 3.7, 3.8, 3.9 and 3.10 on both UNIX and Windows.
+  3.7, 3.8, 3.9 and 3.10 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -221,13 +221,11 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.6`_
 -  `Python 3.7`_
 -  `Python 3.8`_
 -  `Python 3.9`_
 -  `Python 3.10`_
 
-.. _Python 3.6: https://docs.python.org/3.6/
 .. _Python 3.7: https://docs.python.org/3.7/
 .. _Python 3.8: https://docs.python.org/3.8/
 .. _Python 3.9: https://docs.python.org/3.9/
@@ -239,7 +237,7 @@ Supported versions can be found in our ``noxfile.py`` `config`_.
 .. _config: https://github.com/googleapis/python-spanner/blob/main/noxfile.py
 
 
-We also explicitly decided to support Python 3 beginning with version 3.6.
+We also explicitly decided to support Python 3 beginning with version 3.7.
 Reasons for this include:
 
 -  Encouraging use of newest versions of Python 3

README.rst

@@ -56,12 +56,13 @@ dependencies.
 
 Supported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^
-Python >= 3.6
+Python >= 3.7
 
 Deprecated Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 Python == 2.7.
 Python == 3.5.
+Python == 3.6.
 
 
 Mac/Linux