added url patterns
added url href 'signup' that goes to 'SignUp'
added sign up form
added a view class about the 'signup'
added template about the 'signup' that shows 'signup page' and a type about the input(POST)
added test code about signup page
modified test code about invalid_password(previous invalid password 'foobar' is 6-digits)
modified the maximum length of the website_url to 255
test code about modified the maximum length of the website_url to 255
added SMTP settings
added a mailing to new user
added a test about the mailing to new user
added requirments (django-smtp-ssl)
deleted some useless setting, like djcelery-email (we use django-smtp-ssl)
added the test code about sending a mail to new user using celery
added the view about sending a mail to new user using celery
added requirements, 'django-smtp-ssl'
added the tasks to worker about sending a mail to new user using SMTP
modified that the recipient is new user, not buidlbuild
modified that the recipient is who has a valid email