Add a WithContext function (#144)

* Add a WithContext function, Fixes #143

This enables the use of requests with a specific context attached.

* Fix indentation

* Add a test

gitlab.go

@@ -18,6 +18,7 @@ package gitlab
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -546,6 +547,14 @@ func WithSudo(uid interface{}) OptionFunc {
 	}
 }
 
+// WithContext runs the request with the provided context
+func WithContext(ctx context.Context) OptionFunc {
+	return func(req *http.Request) error {
+		req = req.WithContext(ctx)
+		return nil
+	}
+}
+
 // Bool is a helper routine that allocates a new bool value
 // to store v and returns a pointer to it.
 func Bool(v bool) *bool {

gitlab_test.go

 package gitlab
 
 import (
+	"context"
 	"encoding/json"
 	"io/ioutil"
 	"net/http"
@@ -137,3 +138,15 @@ func TestCheckResponse(t *testing.T) {
 		t.Errorf("Expected error: %s, got %s", want, errResp.Error())
 	}
 }
+
+func TestRequestWithContext(t *testing.T) {
+	ctx := context.Background()
+	req, err := NewClient(nil, "").NewRequest("GET", "test", nil, []OptionFunc{WithContext(ctx)})
+	if err != nil {
+		t.Fatalf("Failed to create request: %v", err)
+	}
+
+	if req.Context() != ctx {
+		t.Fatal("Context was not set correctly")
+	}
+}