Add Model Permissions Tests

[dannygoldstein]

This PR adds tests for cesium-ml/baselayer#184 that will be run by the baselayer CI.

[pep8speaks]

Hello @dannygoldstein! Thanks for opening this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file template_app/models.py:

Line 5:42: W291 trailing whitespace
Line 6:29: W291 trailing whitespace
Line 14:1: E302 expected 2 blank lines, found 1
Line 29:6: W291 trailing whitespace
Line 34:80: E501 line too long (89 > 79 characters)
Line 40:6: W291 trailing whitespace
Line 46:42: W291 trailing whitespace
Line 54:6: W291 trailing whitespace
Line 75:6: W291 trailing whitespace
Line 84:1: W391 blank line at end of file

• In the file template_app/tests/conftest.py:

Line 44:1: E302 expected 2 blank lines, found 1
Line 76:80: E501 line too long (81 > 79 characters)
Line 81:80: E501 line too long (80 > 79 characters)

• In the file template_app/tests/fixtures.py:

Line 27:80: E501 line too long (86 > 79 characters)
Line 46:1: W293 blank line contains whitespace
Line 56:1: W293 blank line contains whitespace
Line 60:1: W293 blank line contains whitespace
Line 64:1: W293 blank line contains whitespace
Line 79:1: W293 blank line contains whitespace
Line 80:43: W291 trailing whitespace

• In the file template_app/tests/models/test_models.py:

Line 13:80: E501 line too long (82 > 79 characters)
Line 19:52: W291 trailing whitespace
Line 30:80: E501 line too long (98 > 79 characters)
Line 39:80: E501 line too long (94 > 79 characters)
Line 47:80: E501 line too long (92 > 79 characters)

[dannygoldstein]

Can't assign reviewers, but would be great if @stefanv and/or @acrellin could take a look.

[stefanv]

The template app is supposed to be the one users clone to start out from with baselayer. Thoughts?

These tests are good to add, so I'm tempted to merge this. We need to sort out the CI problems though.

[dannygoldstein]

CI errors are unrelated to current PR:

W: GPG error: http://dl.google.com/linux/chrome/deb stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13
E: The repository 'http://dl.google.com/linux/chrome/deb stable InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: https://packagecloud.io/github/git-lfs/ubuntu trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6B05F25D762E3157
E: The repository 'https://packagecloud.io/github/git-lfs/ubuntu trusty InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: http://ppa.launchpad.net/couchdb/stable/ubuntu/dists/trusty/Release.gpg: Signature by key 15866BAFD9BCC4F3C1E0DFC7D69548E1C17EAB57 uses weak digest algorithm (SHA1)
The command ".travis/travis_install.sh" failed and exited with 100 during .