Apply the fix from @chrizzFTD where we invoke the entry point using
module exec mode on a ``__main__.py`` and import the
``test_example::`main()` from within that entry point script.
A per #98 we need tests for examples from the docs as they would be run
by a user copy and pasting the code. This adds a small system for loading
examples from an "examples/" directory and executing them in
a subprocess while checking the output. We can use this to also verify
end-to-end expected logging output on std streams (ex. logging on
stderr).
To expand this further we can parameterize the test list using the
contents of the examples directory instead of hardcoding the script
names as I've done here initially.
Also, fix up the current readme examples to have the required/proper `if
__name__ == '__main__'` script guard.
Tyler Goodlet