Merge branch 'feature/issue-85-so-that-I-can-communicate-to-all-district-staff-as-a-RTS-staff-role-I-can-send-sms' into feature/issue-90-refactor-send-to-sms-zones-code-to-fix-known-bugs

Conflicts:
	sms/admin.py
Update travis to use wheel (again) after git resets - thanks @jerith (again)
Merge branch 'feature/issue-90-refactor-send-to-sms-zones-code-to-fix-known-bugs' into develop
Merge branch 'feature/issue-88-add-update-school-registration-data-to-the-USSD-menu' into develop
Merge branch 'develop' into feature/issue-89-create-ability-for-district-admin-to-register-on-the-system-via-USSD