Remove non-standard "type annotations"

Since we're not actually using Flow.

lib/util.js

@@ -1,6 +1,6 @@
 
 // Converts "accessToken" to "Access Token"
-export function camelCaseToRegularForm(camelCase: string): string {
+export function camelCaseToRegularForm(camelCase) {
   return camelCase
     // insert a space before all caps
     .replace(/([A-Z])/g, ' $1')