fix golint and go vet warnings

[feliixx]

The contributions guidelines states that

Code should pass golint, go vet and go fmt

Currently, 6 files aren't formatted with go fmt, golint returns 126 warnings and go vet returns 486 warnings!
It would be nice to fix this in order to run gloint/go vet against new code direclty in travis

If you're interrested in this I'll send a PR!

[domodwyer]

Hey @feliixx!

We're definitely interested in a PR - we know the pre-fork code is not exactly go vet friendly...

On a side note I'm at a database conference this week and a few people asked about 3.4 support - I credited you for the hard work :)

Dom

[domodwyer]

Thanks again @feliixx, this was a serious undertaking!