FittedCloud Go1.6 support

This patch adds Go1.6 support to the FittedCloud storage driver.

.travis.yml

@@ -2,6 +2,7 @@ go_import_path: github.com/codedellemc/libstorage
 
 language: go
 go:
+  - 1.6.3
   - 1.7.5
   - 1.8
   - tip
@@ -16,8 +17,9 @@ env:
 
 matrix:
   allow_failures:
-    - go:  1.7.5
-    - go:  tip
+    - go: 1.6.3
+    - go: 1.7.5
+    - go: tip
   fast_finish: true
 
 before_install:

drivers/storage/fittedcloud/utils/utils_pre_go17.go

@@ -0,0 +1,23 @@
+// +build !go1.7
+// +build !libstorage_storage_driver libstorage_storage_driver_fittedcloud
+
+package utils
+
+import (
+	"net/http"
+
+	"golang.org/x/net/context/ctxhttp"
+
+	"github.com/codedellemc/libstorage/api/types"
+)
+
+func doRequest(ctx types.Context, req *http.Request) (*http.Response, error) {
+	return doRequestWithClient(ctx, http.DefaultClient, req)
+}
+
+func doRequestWithClient(
+	ctx types.Context,
+	client *http.Client,
+	req *http.Request) (*http.Response, error) {
+	return ctxhttp.Do(ctx, client, req)
+}