Methtuple

- Fixed parsing of reads containing insertions (closes [104](https://github.com/PeteHaitch/methtuple/issues/104))
- Fixed handling of gzip and bzip output files and filenames
- Remove support for Python 2.7. It may still work, but I'm no longer going to try to maintain compatability with both Python 2 and 3.

- Fixed parsing of `--methylation-type` argument (closes [102](https://github.com/PeteHaitch/methtuple/issues/102))

`methtuple` now requires pysam `v0.8.4` or greater.
`methtuple` now support Python 3.5.

Bug fixes

- Fixed failing tests due to changes between pysam v0.8.3 and v0.8.4.

Internal

- `methtuple` now requires pysam `v0.8.4` or greater

`methtuple` now requires pysam `v0.8.3` or greater.

Bug fixes

- Fixed failing tests due to changes between pysam v0.8.2 and v0.8.3.

Internal

- `methtuple` now requires pysam `v0.8.3` or greater

`methtuple` now requires `pysam v0.8.1` or greater.

Bug fixes

* Fixed Python 3 compatibility issues due to changes in the `pysam` API (closes [94](https://github.com/PeteHaitch/methtuple/issues/94)).

Internal

Moved to the new `pysam` API. As a result, `methtuple` now requires `pysam v0.8.1` or greater.

This version of the software changes the name from `comethylation` to `methtuple` to better reflect what it actually does.

I have also switched to the MIT licence.

New or improved features

* Added `--all-combinations` option to create all possible m-tuples including non-neighbouring ones. This will greatly increase the memory usage if combined with larger values of `--m` (e.g. > 2).