Fix tests that are broken with the latest version of NSoT

[nickpegg]

• Bump nsot to current latest version
• Fix capitalization in test_site_add()
• Fix wrong network in test_networks_subcommands()
  • 10.10.10.0/24 should be the parent network since it gets created on line 678
• Fix wrong networks in test_networks_allocation()
  • 10.20.30.1/32 is assigned, so 10.20.30/28 should be off-limits

The cases of incorrect networks were modified based on my interpretation of the test code. Please let me know if I'm wrong and they truly should be the old values.

[nickpegg]

So tests weren't actually directly broken in master, they just started failing for me locally because I had upgraded NSoT to latest on my local machine (long story short, cryptography doesn't build with latest libssl). We definitely should be testing against latest NSoT though, so these should definitely be fixed.

From digging into the root causes here to make sure this PR is justified:

• The capitalization change is from a change in NSoT where the error now returns a dict, whose contents aren't title()'d. We generally want App.pretty_dict() to not mess with the values of the given dict, so I'm leaving the test to expect the lowercased "site".
• The failure in test_nteworks_subcommands() was due to a behavior change (fixing a bad behavior) in the bugfix dropbox/nsot#210
• The failure in test_networks_allocation() is due to me fixing a bug where addresses in the assigned state, such as those assigned to interfaces, were considered for allocation

Overall I feel confident that the way I fixed these tests is the correct way