Use errcheck to find unhandled errors (#795)

Signed-off-by: Chris Cummer <chriscummer@me.com>

vendor/github.com/google/go-github/v26/github/github.go

@@ -527,7 +527,7 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) (*Res
 
 		return nil, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	response := newResponse(resp)
 

vendor/github.com/gophercloud/gophercloud/pagination/http.go

@@ -21,7 +21,8 @@ type PageResult struct {
 func PageResultFrom(resp *http.Response) (PageResult, error) {
 	var parsedBody interface{}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
+
 	rawBody, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
 		return PageResult{}, err