Implements email confirmation

Support for confirming initial email address, as well as changing a
confirmed email address (confirmed email address will remain on record
until provisional address is confirmed).

Adds emailConfirmed field to User model, and corresponding database
migration.

Small changes to the email module.

Updates requirements.txt and config.sample.py.
Try removing whatever is currently in the email field from the database. I think there's some issue if it's an empty string and marked unverified. 

--Daniel

On Tue, Sep 30, 2014 at 1:09 AM, Brandon Sato <notifications@github.com>
wrote:

>>      return render_template('editprofile.html',
>>          form = form, authorize_url = g.authorize_url)
>>  
>> +@app.route('/confirm/<token>')
>> +@login_required
>> +def confirm(token):
>> +    if current_user.confirm(token):
>> +        print(current_user.email)
>> +        flash('You have successfully confirmed your email address.  Thanks!')
> Need style arguments here and on the expiration flash, ie ``'success'```and ```'danger'```
> ---
> Reply to this email directly or view it on GitHub:
> https://github.com/brandonsato/cbbpoll/pull/14/files#r18203808