drop python < 3.6 for opencensus-ext-stackdriver (#1056)

* drop python < 3.6 for opencensus-ext-stackdriver

* Update contrib/opencensus-ext-stackdriver/CHANGELOG.md

Author: aabmass

contrib/opencensus-ext-stackdriver/CHANGELOG.md

@@ -2,30 +2,33 @@
 
 ## Unreleased
 
+- Drop python <3.6 in opencensus-ext-stackdriver
+  [#1056](https://github.com/census-instrumentation/opencensus-python/pull/1056)
+
 ## 0.7.4
 Released 2020-10-14
 
-  - Change default transporter in stackdriver exporter
-  ([#929](https://github.com/census-instrumentation/opencensus-python/pull/929))
+- Change default transporter in stackdriver exporter
+([#929](https://github.com/census-instrumentation/opencensus-python/pull/929))
 
 ## 0.7.3
 Released 2020-06-29
 
-  - Add mean property for distribution values
-  ([#919](https://github.com/census-instrumentation/opencensus-python/pull/919))
+- Add mean property for distribution values
+([#919](https://github.com/census-instrumentation/opencensus-python/pull/919))
 
 ## 0.7.2
 Released 2019-08-26
 
-  - Delete SD integ test metric descriptors
-  ([#770](https://github.com/census-instrumentation/opencensus-python/pull/770))
-  - Updated `http.status_code` attribute to be an int.
-  ([#755](https://github.com/census-instrumentation/opencensus-python/pull/755))
+- Delete SD integ test metric descriptors
+([#770](https://github.com/census-instrumentation/opencensus-python/pull/770))
+- Updated `http.status_code` attribute to be an int.
+([#755](https://github.com/census-instrumentation/opencensus-python/pull/755))
 
 ## 0.7.1
 Released 2019-08-05
 
-  - Support exporter changes in `opencensus>=0.7.0`
+- Support exporter changes in `opencensus>=0.7.0`
 
 ## 0.4.0
 Released 2019-05-31

contrib/opencensus-ext-stackdriver/setup.py

@@ -27,11 +27,7 @@
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
@@ -46,6 +42,7 @@
         'rsa <= 4.0; python_version<="3.4"',
         'opencensus >= 0.8.dev0, < 1.0.0',
     ],
+    python_requires=">=3.6",
     extras_require={},
     license='Apache-2.0',
     packages=find_packages(exclude=('examples', 'tests',)),

tox.ini

@@ -6,6 +6,9 @@ envlist =
   py39-setup
   py39-docs
 
+[constants]
+unit-base-command = py.test --quiet --cov={envdir}/opencensus --cov=context --cov=contrib --cov-report term-missing --cov-config=.coveragerc --cov-fail-under=96.5 --ignore=contrib/opencensus-ext-datadog tests/unit/ context/ contrib/
+
 [testenv]
 install_command = python -m pip install {opts} {packages}
 
@@ -38,7 +41,7 @@ deps =
   unit,lint,bandit: -e contrib/opencensus-ext-pyramid
   unit,lint,bandit: -e contrib/opencensus-ext-requests
   unit,lint,bandit: -e contrib/opencensus-ext-sqlalchemy
-  unit,lint,bandit: -e contrib/opencensus-ext-stackdriver
+  py3{6,7,8,9}-unit,lint,bandit: -e contrib/opencensus-ext-stackdriver
   unit,lint,bandit: -e contrib/opencensus-ext-threading
   unit,lint,bandit: -e contrib/opencensus-ext-zipkin
   unit,lint,bandit: -e contrib/opencensus-ext-google-cloud-clientlibs
@@ -50,7 +53,9 @@ deps =
   docs: sphinx >= 1.6.3
 
 commands = 
-  unit: py.test --quiet --cov={envdir}/opencensus --cov=context --cov=contrib --cov-report term-missing --cov-config=.coveragerc --cov-fail-under=97 --ignore=contrib/opencensus-ext-datadog tests/unit/ context/ contrib/
+  py3{6,7,8,9}-unit: {[constants]unit-base-command}
+  py{27,34,35}-unit: {[constants]unit-base-command} --ignore=contrib/opencensus-ext-stackdriver
+
   ; TODO system tests
   lint: isort --check-only --diff --recursive .
   lint: flake8 context/ contrib/ opencensus/ tests/ examples/