removes dependencies

[chris-ramon]

Overview

• vendor: removes vendor directory, until now we were using two dependencies:
  • https://github.com/kr/pretty - for debugging, to check diff from expect & actual tests, we can always use this awesome lib, when working on this lib for debugging.
  • golang.org/x/net/context" - for context support, but dependency was removed via: Use standard library's "context" package #214, since go1.7+ included in the std lib.
• testutil: updated Diff, to just return want & got, instead of the actual diff, now output looks like this, Eg:

--- FAIL: TestBasicGraphQLExample (0.00s)
        graphql_test.go:131: wrong result, query: { hello }, graphql result diff: [
                got: &{map[hello:world] []}
                want: map[hello:worldz]
                ]

Test plan

• go test ./...

[coveralls]

Coverage increased (+0.03%) to 82.129% when pulling 439c1ad on no-dependencies into a498c85 on master.