Autorank

Some small fixes and improvements

- Minimal versions for matplotlib, scipy, statsmodels, and pandas defined
- Beautified string output of results
- Added a warning in case the matplotlib option text.usetex is True
- Fixed some typos

Feature complete and stable version of Autorank.

Future changes will be downward compatible.

This release contains the following changes:
- import is no simplified to from autorank import autorank
- Allow to define if ranking is ascending or descending

This releases fixes the following problems:
- Prevents buffer over and underflows for the calculation of non-parametric confidence intervals. This could happen in case there were only few samples in the populations.

This release adds the following features:
- Generation of written reports
- Latex output of results
- Improved documention.

This release adds the following features:
- Support for the generation of CD diagrams for the Nemenyi test, and CI diagrams for the Tukey HSD and paired t-test.
- Automated generation of a natural language report of the results of the statistical tests.