reworking CONTRIBUTING to be more than bullet points
add some new sections

expanded on "How is the codebase organised?" and "What needs to be done?"
added notes about integration tests
moved project structure notes in
removed project structure, moved contributing up
dropped 'submitting an issue' section
added deployment doc
removed deployment section
word wrapping
added git push command
Added some tips for pull requests and grabbing issues
Merge pull request #359 from octokit/cleanup-laughing-octo-sansas

reworking CONTRIBUTING to be more than bullet points