Remove redundant string functions

Author: limzykenneth

src/utilities/array_functions.js

@@ -1,11 +1,9 @@
-import arrayFunctions from './array_functions.js';
 import conversion from './conversion.js';
-import stringFunctions from './string_functions.js';
+import utilityFunctions from './utility_functions.js';
 import timeDate from './time_date.js';
 
 export default function(p5){
-  p5.registerAddon(arrayFunctions);
   p5.registerAddon(conversion);
-  p5.registerAddon(stringFunctions);
+  p5.registerAddon(utilityFunctions);
   p5.registerAddon(timeDate);
 }