Porting driver to new repo
Added: forgot FinishPurchase controller
Added: automated emails for when the stacker is full, cassette is missing or maintenance is required
Formatting of emails updated to spec
Added: low balance email
Fixed: updated driver to reflect fixes from prior development
Merge branch 'master' into new-driver

Conflicts:
	assets/css/skyhook.css
Merge branch 'master' into new-driver
Added: JSON_BIGINT_AS_STRING shim
Fixed: Bill scanner driver can now accept bills of the same type consecutively
Fixed: low balance alert now uses bitcoin balance instead of fiat estimate in email
Merge branch 'new-driver'

Conflicts:
	includes/JSON.php
Fixed: if there are not enough funds to start a transaction, redirect to minimum balance page
Merge remote-tracking branch 'upstream/master'