This release fixes a few bugs and adds a few features
* output statistics of different iterations of the treetime optimization loop (trace-log, thanks to ktmeaton)
* speed ups by akislyuk
* fix errors with dates in the distant future
* better precision of tabular skyline output
* adds clock-deviation to the root-to-tip output of the `clock` command
0.8.1 -- bug fixe amino acid profile map.
0.8.0 -- drop python 2.7 support, bug fixes.
0.7.6 -- catch of distributions are too short for calculating confidence intervals.