Add coverity-scan script
Tweak travis secure config
Add coverity scan badge to readme
Only run coverity on development
Refine build limitation
Update README to include Java, PowerShell bindings
Merge pull request #2053 from ethomson/bindings

Update README to include Java, PowerShell bindings
Merge pull request #2044 from libgit2/coverity

Run Coverity scan on Travis