v1.3.0 - Added `async_sync`, `run_sync` + More

asyncx.py

• Added async_sync decorator for easily running async functions/methods from
  non-async functions/methods. Useful for unit tests.
• Added run_sync function, mainly intended for running async functions from the REPL with ease

common.py

• Added dec_round for rounding Decimal objects to arbitrary DP
• Added env_cast, env_int, and env_decimal
• Added chunked function for slicing a list into multiple equal sized lists
• Added Dictable abstract class - eases creating Python 3.7 dataclass objects from dict's
  as well as converting them back into dict's

tests.py

• Added new TestGeneral test case, for unit testing some of the new functions

Documentation

• Added docs for asyncx module
• Updated common module to include new functions/classes
• Fixed docs for tests
• Various cleanup to reduce warnings from Sphinx