Switch to Go stdlib's context package

* Requires Go 1.7 or higher

Author: dghubble

config.go

@@ -1,13 +1,12 @@
 package oauth1
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"net/url"
-
-	"golang.org/x/net/context"
 )
 
 const (

config_test.go

@@ -1,13 +1,13 @@
 package oauth1
 
 import (
+	"context"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"golang.org/x/net/context"
 )
 
 const expectedVerifier = "some_verifier"

context.go

@@ -1,9 +1,8 @@
 package oauth1
 
 import (
+	"context"
 	"net/http"
-
-	"golang.org/x/net/context"
 )
 
 type contextKey struct{}

context_test.go

@@ -1,11 +1,11 @@
 package oauth1
 
 import (
+	"context"
 	"net/http"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"golang.org/x/net/context"
 )
 
 func TestContextTransport(t *testing.T) {