Remove <rootpath>/vendor/ prefix from vendored packages

[dimroc]

Fixes #8

---

As seen here where we are using golang/dep to vendor our dependencies: smartcontractkit/chainlink#680 (comment)

Source

package store

import (
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
)

//go:generate gencodec -type Log -field-override logMarshaling -out output.go

type Log struct {
	Address common.Address `json:"address" gencodec:"required"`
	// list of topics provided by the contract.
	Topics []common.Hash `json:"topics" gencodec:"required"`
	// supplied by the contract, usually ABI-encoded
	Data []byte `json:"data" gencodec:"required"`
}

type logMarshaling struct {
	Data hexutil.Bytes
}

Before

// Code generated by github.com/fjl/gencodec. DO NOT EDIT.

package store

import (
	"encoding/json"
	"errors"

	"github.com/smartcontractkit/chainlink/vendor/github.com/ethereum/go-ethereum/common"
	"github.com/smartcontractkit/chainlink/vendor/github.com/ethereum/go-ethereum/common/hexutil"
)

...

Now

// Code generated by github.com/fjl/gencodec. DO NOT EDIT.

package store

import (
	"encoding/json"
	"errors"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
)

...

---

It has been difficult to reproduce the error in the test suite because this project does not use golang/dep to vendor dependencies.

[fjl]

Sorry, I've been really slow catching up with GH notifications. I don't think this is a good solution. We should try to remove the use of goimports instead.