Assorted pre-Black fixes

Assorted pre-Black fixes

Fixes to the test suite, a few errant imports, and setup.py:

- mysql and postgresql have unused 'json' imports; remove
- postgresql is exporting the 'json' symbol, remove
- make sure setup.py can find __version__ using " or '
- retry logic in provision create database for postgresql fixed
- refactor test_magazine to use cls.tables rather than globals
- remove unused class in test_scoping
- add a comment to test_deprecations that this test suite itself
  is deprecated
- don't use mapper() and orm_mapper() in test_unitofwork, just
  use mapper()
- remove dupe test_scalar_set_None test in test_attributes
- Python 2.7 and above includes unittest.SkipTest, remove pre-2.7
  fallback
- use imported SkipTest in profiling
- declarative test_reflection tests with "reflectable_autoincrement"
  already don't run on oracle or firebird; remove conditional logic
  for these, which also removes an "id" symbol
- clean up test in test_functions, remove print statement
- remove dupe test_literal_processor_coercion_native_int_out_of_range
  in test/sql/test_types.py
- fix psycopg2_hstore ref

Change-Id: I7b3444f8546aac82be81cd1e7b6d8b2ad6834fe6