Assertpy

- support Python 3.6 (62)
- correct support for metaclass testing with `is_type_of()` (57)
- better failure with `fail()` (58)
- new `soft_fail()` assertion (59)

- **API Breakage!** rename `assert_soft()` to `assert_warn()` (commit 9983b3a)
- new `is_subset_of()` assertion (48)
- extend `is_subset_of()` to work with dicts (50, PR 51)
- support ABC Metaclass in `is_type_of()` and `is_instance_of()` (52)
- dynamic attribute assertions for dicts (49)
- new `contains_only()` assertion (54)
- new _correct_ impl of soft assertions using the `with soft_assertions():` context manager (53, PR 55)
- updated docs

- **API Breakage!** rename `extract()` helper to `extracting()` (42)
- new expected exceptions using `raises()` and `when_called_with()` syntax (41)
- new `is_iterable()` assertion (45)
- support Python 3.5, drop support for Python 3.3 (43)
- fix `extracting()` helper so it can flatten a collection of dicts on key (44)
- loosen type checking for dict assertions (like `contains_key()`, `contains_value()`, ..) to be merely _dict-like_ (46)
- make `starts_with()` and `end_with()` work with collections (24)
- new _soft_ assertions print warning message instead of raising `AssertionError`

- single codebase with support for Python 2.6, 2.7, 3.3, 3.4 (36)
- added `contains_ignoring_case()` (37)
- added custom error messages via `described_as()` (35)

- added `does_not_contain_entry()` (34)
- added `does_not_contain_key()` and `does_not_contain_value()` (33)
- relaxed numeric type checking to work with things like `numpy.float64` (32)
- added `contains_duplicates()` and `does_not_contain_duplicates()` (31)
- added `is_not_in()` (29)
- added `is_in()` (28)
- added `is_zero()` and `is_not_zero()` (27)
- added `is_greater_than_or_equal_to()` and `is_less_than_or_equal_to()` (26)
- added `contains_sequence()` (25)
- added `is_positive()` and `is_negative()` (23)

- minor error message cleanups
- initial release on Anaconda Cloud (aka binstar)