Pytest-check

Fixed

- While using the `check` fixture, allow `check.check` as a context manager.
- this is unnecessary, the `check` fixture now works as a context manager.
- but apparently some people have been using `with check.check:`
- so this fix makes that work.

Added

- Allow `raises` from `check` object.
- Now `with check.raises(Exception):` works.

Changed

- README update

Added

- Red output in pseudo-traceback

Changed

- Refactored code into more modules
- All functionality now possible through `check` fixture or `from pytest_check import check`.
- The `check` object from either of these methods can be used as either a context manager or to access the check helper functions.
- Lots of rewrite in README

Deprecated
- API change.
- Access to check helper functions via `import pytest_check as check` is deprecated.
- It still works, but will be removed in a future version.
- However, there is no deprecation warning for this.

Fixed

- [issue 80](https://github.com/okken/pytest-check/issues/80) --tb=no should remove tracebacks from xml output

Fixed

- [issue 55](https://github.com/okken/pytest-check/issues/55) a problem with multiple drive letters.
- code is using `os.path.relpath()`, but sometimes it can fail.
- when it does fail, fall back to `os.path.abspath()`.
- thanks [rloutrel](https://github.com/rloutrel) and [kr1zo](https://github.com/kr1zo) for your patience and persistence, and for the solution.