Same as my other review concern - can we guarantee that this will exit without putting our full trust in Bitbucket to do the right thing?

No space before the """.

Can be one statement.

Blank line before this.

Blank line before this.

BLANK LINE BEFORE THIS.

One variable setting per line.
Same below.

Blank line between these.

next is a reserved word.

We don't use the if .. else .. form in our code. Should just be a standard if statement.

The """ should go on the previous line.

Blank line before this.

Blank line before this.

No u prefixes.

And this.

A quicker and nicer way of doing this is:
results = [
    Branch(...)
    for name, info in six.iteritems(branches)
]

You then won't need to set results = [] above.
Also note the six.iteritems. We use a module called six to provide compatibility with Python 3. One of the things we must use it for is any iter* function.
If you do any iteration anywhere else in your code (I may have missed these), please update them to use six.

You can just do:
if not results:

And this.

This line is too long. Maybe shorten the summary and go into more detail in the description.

Blank line above.

Blank line before this.

Did you mean to capitalize all of "THE" ?

And this.

Blank line before this.