Update flask-wtf to 0.13.1

[pyup-bot]

There's a new version of Flask-WTF available.
You are currently using 0.12. I have updated it to 0.13.1

These links might come in handy: PyPi | Changelog | Repo | Docs

Changelog

0.13.1

---

Released 2016/10/6

• Deprecation warning for Form is shown during __init__ instead of immediately when subclassing. (262_)
• Don't use pkg_resources to get version, for compatibility with GAE. (261_)

.. _261: pallets-eco/flask-wtf#261
.. _262: pallets-eco/flask-wtf#262

0.13

---

Released 2016/09/29

• Form is renamed to FlaskForm in order to avoid name collision with WTForms's base class. Using Form will show a deprecation warning. (250_)
• hidden_tag no longer wraps the hidden inputs in a hidden div. This is valid HTML5 and any modern HTML parser will behave correctly. (217, 193)
• flask_wtf.html5 is deprecated. Import directly from wtforms.fields.html5. (251_)
• is_submitted is true for PATCH and DELETE in addition to POST and PUT. (187_)
• generate_csrf takes a token_key parameter to specify the key stored in the session. (206_)
• generate_csrf takes a url_safe parameter to allow the token to be used in URLs. (206_)
• fom.data can be accessed multiple times without raising an exception. (248_)
• File extension with multiple parts (.tar.gz) can be used in the FileAllowed validator. (201_)

.. _187: pallets-eco/flask-wtf#187
.. _193: pallets-eco/flask-wtf#193
.. _201: pallets-eco/flask-wtf#201
.. _206: pallets-eco/flask-wtf#206
.. _217: pallets-eco/flask-wtf#217
.. _248: pallets-eco/flask-wtf#248
.. _250: pallets-eco/flask-wtf#250
.. _251: pallets-eco/flask-wtf#251

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[noirbizarre]

Needs some code update to avoid deprecation warnings.

Related to #586

[pyup-bot]

Closing this in favor of #665