Add Flask-RESTful to requirements for Craton

- Is the library actively maintained?

  The last PyPI release was in December of 2015 but the source
  repository [1] has been committed to as recently as December of 2016.

- Is the library good code?

  Yes. It's well tested and they use Travis CI for continuous testing.
  They also have 96% test coverage.

- Is the library python 3 compatible?

  Yes. They support Python 2.6, 2.7, 3.3, 3.4, and 3.5. They do not seem
  to have started testing against 3.6.

- Is the library license compatible?

  Yes. It's licensed as BSD.

- Is the library already packaged in the distros we target (Ubuntu
  latest / Fedora latest)?

  Ubuntu: Yes [2]
  Fedora: Yes [3]
  Gentoo: Yes [4]
  SUSE: No

- Is the function of this library already covered by other libraries
  in ``global-requirements.txt``?

  No. There's nothing comparable in global-requirements.txt

- Is the library required for OpenStack project or related dev or
  infrastructure setup? (Answer to this should be Yes, of course)
  Which?

  Yes. Craton. We opted into the global requirements sync job and it has
  been failing due to this being a requirement that we were using prior
  to opting in. See bug 1656541 for more details.

[1]: https://github.com/flask-restful/flask-restful/
[2]: http://packages.ubuntu.com/search?keywords=flask-restful&searchon=names&suite=all&section=all
[3]: https://apps.fedoraproject.org/packages/s/flask-restful
[4]: https://packages.gentoo.org/packages/dev-python/flask-restful

Related-bug: #1656541
Change-Id: I56f2f027f7a877ec2a3c9504f320aee2ca0b0629

global-requirements.txt

@@ -54,6 +54,7 @@ extras  # MIT
 fairy-slipper>=0.1.0  # Apache-2.0
 falcon>=0.1.6  # Apache-2.0
 Flask>=0.10,!=0.11,<1.0  # BSD
+Flask-RESTful>=0.3.5     # BSD
 fortiosclient>=0.0.2 # Apache-2.0
 futures>=3.0;python_version=='2.7' or python_version=='2.6'  # BSD
 futurist>=0.11.0,!=0.15.0  # Apache-2.0

upper-constraints.txt

@@ -3,6 +3,7 @@ Babel===2.3.4
 CouchDB===1.1
 Django===1.8.17
 Flask===0.12
+Flask-RESTful===0.3.5
 GitPython===2.1.1
 Jinja2===2.8.1
 Mako===1.0.6