Fix unit tests

Update change log

TheHive-Project#170 Fix docs

Update change log for 1.7.1 patch release

Remove duplicate function.

Create bulk-alert-merge-to-case.py (TheHive-Project#95)

A sample script to mass merge alerts into a single case

Tag 1.5.3

Tag 1.5.2

Remove pandoc from pip requirement and install it via apt

Update changelogs