Sending email from discrepancy checking cron job

(#245)
python sandbox should be optional
align UI..
Merge remote-tracking branch 'upstream/master'
Reacting to code review (#245).
Merge remote-tracking branch 'upstream/master'
tour fix
Merge pull request #259 from anubhavsinha/tour_fix

tour fix
Merge remote-tracking branch 'upstream/master'
Reacting to code review (#245).
Merge pull request #251 from egor83/master

Sending email from discrepancy checking cron job
reformatted admin.py for pep8, and replaced has_python to has_sandbox etc.
Merge pull request #254 from anubhavsinha/python_sandbox

python sandbox should be optional