Assertpy

- hide verbose traceback messages in pytest (100)
- fixup dict equality when including/ignoring deeply nested keys (101)
- fixup dynamic dict assertions when key are dict methods (105)
- dict equality errors now sort the keys in the error message (cf2f7d5)
- fixup docs
* fixup readme typo (102)
* docs for dict equality with nested keys (88877a1)
* write docs for how to generate sphinx docs (2fbd42a)
* add sphinx Note section to snapshot docs (8fe8eff)

- add `is_sorted()` assertion (99)
- fixup code formatting to be [PEP8](https://www.python.org/dev/peps/pep-0008/) (7684d45)
- lots of docs for v1.0
* add sphinx (e56ea0f)
* write sphinx docs for all assertions (38)
* docs here: https://assertpy.github.io/docs.html

* support Python 3.7 & 3.8 (83, 98)
* enhance `extracting()` with list extract by index (81, d02b53e)
* add kwargs support to `contains_entry()` (85)
* fix deprecated `collections.Iterable` (90)
* fix `is_subset_of()` when invoked with 1-item arg (93)
* enhance `soft_assertions()` context manager to be reentrant (92, 94)
* massive refactor using mixin classes (95)
* all new extension system to support user-defined assertions (96)
* change `assert_warn()` to log instead of print (97)
* doc improvements (84, 91)

* add `is_not_close_to()` and `is_not_between()` (82)
* new `include` flag when comparing `dict`s with `is_equal_to()` (79)
* add file `does_not_exist()` (78)
* update docs, including how regex inline flags work (80)

* snapshot testing (74, [docs](https://github.com/ActivisionGameScience/assertpysnapshot-testing))
* much improved and actually useful `is_equal_to()` failure message when testing `dict`s (75)
* drop Python 2.6 support (76)
* bug fixes (77)
* support for confa-forge packaging (73)

- new numeric assertions `is_nan()`, `is_not_nan()`, `is_inf()`, `is_not_inf()` (66)
- less verbose traceback when using `py.test` (67)
- better `contains()` failure messages, and less verbose (68, 9474760)
- `raises()` assertion supports any callable (70)
- enhance `extracting()` helper with `filter` and `sort` (71, [docs](https://github.com/ActivisionGameScience/assertpyextracting-and-filtering))
- cleanup internals