Some code improvements

* Some assignments simplified by using assignment operators
* Rewrite switch statement with only one case as if.
* Rewrite if-else chain as a switch statement.
* go fmt `modules/todoist/project.go` file.

modules/jenkins/client.go

@@ -46,8 +46,8 @@ func (widget *Widget) Create(jenkinsURL string, username string, apiKey string)
 	return view, nil
 }
 
-func ensureLastSlash(URL string) string {
-	return strings.TrimRight(URL, "/") + "/"
+func ensureLastSlash(url string) string {
+	return strings.TrimRight(url, "/") + "/"
 }
 
 /* -------------------- Unexported Functions -------------------- */

modules/jenkins/widget.go

@@ -75,7 +75,7 @@ func (widget *Widget) contentFrom(view *View) string {
 		var validID = regexp.MustCompile(widget.settings.jobNameRegex)
 
 		if validID.MatchString(job.Name) {
-			str = str + fmt.Sprintf(
+			str += fmt.Sprintf(
 				`["%d"][%s] [%s]%-6s[white][""]`,
 				idx,
 				widget.RowColor(idx),
@@ -83,7 +83,7 @@ func (widget *Widget) contentFrom(view *View) string {
 				job.Name,
 			)
 
-			str = str + "\n"
+			str += "\n"
 		}
 	}