Change "Begin Activity" to "Next Activity" (last page of an activity)

[#70358066]

https://www.pivotaltracker.com/story/show/70358066
Update .gitignore (Sublime Text project files)
Add buttons for creating a new activity and sequence on home page

[#70161558]
cap task for mysqldump on remotes, ignoring answers, runs, & anonymous

Just pull down the data that makes sense to copy for a DB restore locally.
Allow developers to use mysql2 or sqlite3 active record drivers locally.
Certain versions of mysql don't allow default text / blob values.
Reformat crediting in activities

[#68560072]
Change the secondary color of air pollution theme

[#71693122]
Add the ID number to sequences and activities in all listings

[#71696810]