[firefox_profile] add a random profile name generator

[rpappalax]

A common use case for testing is to launch a 'fresh' profile, but not necessarily one with any particular name other than it be unique.

In that case, we should add a function to generate a random profile name.

[rpappalax]

mozprofile give us: random path (we don't want) + random profile name but not just a random profile name (which is what we want) it will be easier for us to just create a new profile with a random name every time

[pdehaan]

Stealing from the mozprofile.profile code, it looks like they're just using this pseudo logic:

# https://docs.python.org/2/library/tempfile.html#tempfile.mkdtemp

from tempfile import mkdtemp

foo = mkdtemp(prefix='_', suffix='.fftool', dir='_temp/profiles')
print(foo) # _temp/profiles/_mKzlMz.fftool/*

So if the user doesn't specify a profile name, we can use mkdtemp to create a random directory name in the specified dir (in our case something like _temp/profiles). Thankfully, we also have control over the prefix and suffix, so we can do something like ./_temp/profiles/_{RANDOM}.fftool/ so we can easily see which directories were created using random+generated names vs named profiles.

Basically if the user doesn't specify a directory name, we'll create a random directory in the ./_temp/profiles/ directory and set that directory name as the profile name. Easy peas.

[pdehaan]

This should have been fixed via #17. Ref: ./fftool/firefox_profile.py:61 wherein if a profile name was not explicitly passed in, we will create a new profile using "fftool.{sha}" (using mkdtemp).