Some parts of the code use 'error' instead of 'err'

[mbfr]

This is a minor issue, but some of the code uses error instead of err which conflicts with the builtin error interface type, as well as not being in line with the Go style

[mbfr]

eg

git2go/git.go

Line 203 in 2fd0495

slice, error := hex.DecodeString(s)

[suhaibmujahid]

Thank you @mbfr for reporting this. I will open a PR to fix the variable names.