remove some duplicate READMEs from tests
since we don't need every one included in the docs
adds detail to the one that remains
MODIFY
tests/venv/py2/README.rst
tests/venv/py2/README.rst
@@ -3,3 +3,7 @@ System - Specifying runtime environments
You can specify runtime environments (such as Python 2 or 3) with a
``runtime.txt`` file.
+
+You can specify just the major version,
+such as `python-2` or `python-3`,
+or a minor version, such as `python-3.5`.

DELETE
tests/venv/py3/README.rst
-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.
-If you need this level of control we recommend you use a `environment.yml`.

DELETE
tests/venv/py35/README.rst
-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 3.5.
-If you need this level of control we recommend you use a `environment.yml`.

remove some duplicate READMEs from tests

since we don't need every one included in the docs

adds detail to the one that remains