Improve setup

I had some trouble setting up opensourcerails to run locally because I hadn't generated the github data, so I added that step to the readme. 

Then generating that data didn't work because I wasn't authenticated with Octokit, but the README made it sound like setting up a .netrc was optional, so I took out the Octokit.netrc = true line from the Rakefile and then getting the github data worked.

But it was hard to tell that generating the data worked because the rake task output a starting statement but never said it was done, so I wasn't sure if it had finished or crashed, so I added a completion output message too.

Love the project!!! <3 <3 <3