python-testtools-2.3.0-4.27

- Add patch to build with python 3.7:
  * testtools-py37.patch

- Allows Recommends and Suggest in Fedora

- Recommends only for SUSE

- update to 2.3.0:
  * Release 2.3.0
  * Add ResourcedToStreamDecorator test result decorator for testresources integration (#243)
  * Make KeysEqual usable with no arguments, i.e. match a dict with no keys. (#241)
  * Add testtools.assertions to the documented API modules (#257)
  * Add Python 3.6 to the list of Travis targets (#255)
  * Don't add file details without content (#252)
  * Don't run Sphinx on Travis Python 3.3 target (#250)
  * Make twistedsupport and tests work on Python 3

- Revert "Require python-unittest2 only for python2". We have now
  a python3-unittest2 package which should be used.

- Require python-unittest2 only for python2

- Change fixtures dependency to "Recommends". It is not a hard
  dependency becauses it causes dependency loops.

- Split documentation and tests into separate .spec file to avoid
  dependency cycle with python-extras/python-testrepositories.

- Converted to single-spec
- Added doc subpackage

- BuildRequires also using extras>=1.0.0