Convert mkv files to mp4

Current version

Revision: 1

mkvtomp4 requires the following formulae to be installed:
gpac 0.7.1 Multimedia framework for research and academic purposes
ffmpeg 3.4.2 Play, record, convert, and stream audio and video
mkvtoolnix 22.0.0_1 Matroska media files manipulation tools
python@2 2.7.14_3 Interpreted, interactive, object-oriented programming language

Recent formula history

ilovezfs mkvtomp4: depend on python@2
ilovezfs mkvtomp4: rename python@2 dependency
ilovezfs mkvtomp4: depend on python instead of :python
Mike McQuaid Use hash rockets again. (#5177)
Mike McQuaid Use Ruby 1.9+ symbol hash keys in all formulae. (#4942)

Formula code at GitHub