implemented "show trace view" feature to open the trace view in browser

Hey there.

Looking for an alternative for the apigee online editor I stumbled upon your sublime package. Great work! Exactly what I was looking for.

I thought it would be useful to have the trace tool just one click away since this would be the first thing I would open once I deploy a new proxy...
So I added a new command which opens a configured uri (configurable in deploy_vars.json, automatically customized with the organization and proxy name) in a new tab of the system standard browser.

I'm a total python noob, so my code might not be as clean as it could be. I appreciate any advice!

I successfully tested the feature in OSX and Windows 7.

What do you think about it?

Cheers, Tim.