Mamba

* Just a little fix for pypi installation :)

* Add filtering support using tags
* Use new execution context for every example. Properties on self are never shared
* Changed execution model
* Added functions for description, it, context, before, after for making mamba more friendly to PEP8 checkers
* Removed subject autoinstantiation
* Removed filewatch feature, use entr or other similar utility
* Dropped Python 2.6 support

* Check for python 3.5
* Stick only minimal dependencies versions
* Allow loading of local non-installed modules and packages

* Show spec filename in each error
* Use .coveragerc file
* Run examples in natural order

* Added Python 2.6 support

* Upgrade coverage
* Fix error reporting in hooks
* Add support for mock.patch