Show check results in status bar on cursor line change

[mrmurphy]

I love using the keyboard and avoiding the mouse when possible. It's especially necessary for people with RSI problems.

This pull request shows check results in the status bar when the cursor is on a line with a flow check result.

That's all! :tada:

[lukehoban]

I think the better way to do this will be to integrate the error reporting with atom-linter per #2, which should provide this behaviour and more niceties.

[mrmurphy]

Sounds good. Thanks!