add wildcard to browsers option (fixes #150)

[christopherjbaker]

This adds a * options to the browsers option, pulling that information from launchpad.

I added a test for it, which passes locally, but chrome and chromium will not pass (they just time out, even waiting a full minute) on travis (besides those and firefox, it also sees phantom, which also passes). I tried googling how to use chrome with travis, but it didn't help. Googling chromium with travis revealed nothing.

[andrejewski]

We will need to remove the failing browsers from the test somehow. Either by having launchpad do more extensive filtering of browsers to return so chrome/chromium are not used or by having an exclude: [browsers] option. I would prefer the former because we shouldn't be testing on browsers that don't exist and exclusion is a game of whack-a-mole.

I do not want this wild card functionality. I don't want my tests to be dynamic to the environment they are on; a environment with no browsers passes the tests. Everyone should be explicit in what browsers they test on. I think we should reconsider adding this feature.

[christopherjbaker]

For your later comment, I would propose that that an empty browsers list be a fail, not a pass.

[christopherjbaker]

per @phillipskevin and @andrejewski, I am closing this as an un-needed feature.