readmes in py3 venv tests
remove outdated note about not being able to pick a Python 3.x
MODIFY
tests/venv/py3/README.rst
tests/venv/py3/README.rst
@@ -4,6 +4,5 @@ System - Specifying runtime environments
You can specify runtime environments (such as Python 2 or 3) with a
``runtime.txt`` file.
-This is an example that selects Python 3. Currently you can not use
-this to select a sepcific version of Python 3 (e.g. 3.4 vs 3.6). If you
-need this level of control we recommend you use a `environment.yml`.
+This is an example that selects Python 3.
+If you need this level of control we recommend you use a `environment.yml`.

MODIFY
tests/venv/py35/README.rst
tests/venv/py35/README.rst
@@ -4,6 +4,5 @@ System - Specifying runtime environments
You can specify runtime environments (such as Python 2 or 3) with a
``runtime.txt`` file.
-This is an example that selects Python 3. Currently you can not use
-this to select a sepcific version of Python 3 (e.g. 3.4 vs 3.6). If you
-need this level of control we recommend you use a `environment.yml`.
+This is an example that selects Python 3.5.
+If you need this level of control we recommend you use a `environment.yml`.

readmes in py3 venv tests

remove outdated note about not being able to pick a Python 3.x