infodeck: replace jasmine with mocha

pull from drafts b747455
infodeck: remove jasmine tests

didn't remove this dir on previous commit. So this should be synced
with drafts b747455
infodeck: set up a test deck for visual testing (drafts pull b85ce1a)
infodeck: reworked the svg import (pull drafts d30477a)
infodeck: deck shows cover if given unknown hash (drafts pull 8dad942)
articles: don't show figure number if no caption
articles: fix intermittent truncation of output file
infodeck: use fontawesome icons in header

from drafts 5bc64eb
infodeck: make so it works on https (thx Danilo)

based on 5bc64eb in drafts but without whitespace changes
article task includes default css location
core: put insert code labels in separate element for different formatting
support for share links
updated ruby and library versions
fixes when unable to build docs in drafts

pull from drafts cc28b21
infodeck: support (and ignore) credits tag

used by catalog processing on main site
skeleton: remove meta tags API
article: support for twitter/facebook metadata

used by bliki at the moment, need to sort out additional data for articles
core: refactored metadata emitter to composition
articles: support article metadata for twitter/facebook
move twitter site id to Site class