Fixed Lab Module + Tests

[nij-patel]

Changes

updated lab.py:

• Use the new lab API (old one lead to nothing), and now Pitt uses an interactive map to show lab statuses. Found the new one by examining network traffic.
• New API (and all other ones on the site) don't return numbers for Mac/Windows/Linux available, so I removed those.
• _fetch_labs() now return dictionary of labs and if they are open or not
• get_status() returns more detailed info about the labs, like how many total machines + how many open

updated lab_test.py:

• old mock data is no longer relevant, so updated/trimmed to two tests
• assert instance of return

Testing

• tested the methods locally and then the tests. all pass locally!

[tianyizheng02]

@nij-patel Did you mean to commit this coverage file?

[tianyizheng02]

Also, is it safe to delete your 154-labs-dev branch?