added missing_phone parameter to users table
skip phone validation when missing phone is set to true
added no_phone scope to User
used better code in missing_phone migration
renamed migration for clarity
updated users with missing_phone if turning on 'require_phone'
added factory for no_phone user and specs for feature
Merge branch 'master' into 1008_require_phone_fix

Resolved an issue w/ the require_phone migration where we weren't checking to
see if AppConfig.first existed (and were therefore getting a NoMethodError)

Conflicts:
	db/schema.rb
Merge pull request #1012 from YaleSTC/1008_require_phone_fix

resolves #1008