boohft-calib 3.0.2 release

The 3.0.2 release is the first stable version.

This version is applicable to any Xbb/cc taggers with user-specified working points, working for all UL year conditions (2016APV, 2016, 2017, and 2018).

Please see the instructions in README. For more technical details, please refer to the BTV talk (accessible by CMS members) referred to in the README. Running on the example card can be a good start to use this tool. As a good reference, the BTV slides also includes several example results, displayed on the CERN EOS website.