Removed the sign out message since we are redirecting now.
Added a clear flash message function.
Updated unplugged videos and pdfs
Removing the function to reduce code.
Merge pull request #196 from nanan9177/blockly_fix

Removed the sign out message since we are redirecting now.
Sign in user when they create an account via course code.
Merge pull request #198 from tobyk100/signin

Sign in user when they create an account via course code.
merge