Updated to API 37.0

Author: daveerickson

fflib/src/classes/fflib_StringBuilder.cls-meta.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
-    <apiVersion>31.0</apiVersion>
+    <apiVersion>37.0</apiVersion>
     <status>Active</status>
 </ApexClass>