Video training baeline

Up until this point I have been maintaining tags that inadvertantly didn't get published (see issue #40) so I am tagging this release as a baseline that corresponds with the creation of the OpenSatKit YouTube channel.

v2.2.0 was the last announced release: https://opensatkit.github.io/journal/Version-2_2-Released.html I am tagging this as v2.2.1 since the only changes have been patches.