Removing SSH key should clear key in dialogue box

[ryanbrainard]

When removing an SSH key from a Heroku account in Eclipse, the key stays in the Eclipse environment even though it is actually removed from Heroku. The SSH key should probably just be loaded directly from the API so Eclipse and Heroku stay in sync.

Steps to Reproduce

1. Setup the plugin with an SSH key added to a Heroku account
2. Open Heroku prefs in Eclipse and click Remove to remove the SSH key from the Heroku account. The key is actually removed (as seen through CLI), but the key remains in the dialogue box which makes it look like the key was never removed.