The typing module on these versions have these issues:
- `typing.Pattern` cannot appear in a Union since it is not considered a
class.
- `@overload` is not supported in runtime. (On the other hand, mypy
doesn't support putting it under `if False`, so we need some runtime
hack).
Refs #5751.
This reverts commit dfe54cd82f.
The idea in the commit was to simplify the code by removing the check
and instead letting it TypeError which has the same effect.
However this type error is caught by mypy, and rather than ignoring the
error we think it's better and clearer to go back to the previous
explicit check.
* Update setup.py requires and classifiers
* Drop Python 2.7 and 3.4 from CI
* Update docs dropping 2.7 and 3.4 support
* Fix mock imports and remove tests related to pypi's mock module
* Add py27 and 34 support docs to the sidebar
* Remove usage of six from tmpdir
* Remove six.PY* code blocks
* Remove sys.version_info related code
* Cleanup compat
* Remove obsolete safe_str
* Remove obsolete __unicode__ methods
* Remove compat.PY35 and compat.PY36: not really needed anymore
* Remove unused UNICODE_TYPES
* Remove Jython specific code
* Remove some Python 2 references from docs
Related to #5275