Add stylechecker rule to ban uses of Class.forName

Author: JoshRosen

scalastyle-config.xml

@@ -150,6 +150,17 @@ This file is divided into 3 sections:
       // scalastyle:on println]]></customMessage>
   </check>
 
+  <check customId="classforname" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
+    <parameters><parameter name="regex">Class\.forName</parameter></parameters>
+    <customMessage><![CDATA[
+      Are you sure that you want to use Class.forName? In nearly all cases, you should use Utils.classForName instead.
+      If you must use Class.forName, wrap the code block with
+      // scalastyle:off classforname
+      Class.forName(...)
+      // scalastyle:on classforname
+    ]]></customMessage>
+  </check>
+
   <!-- ================================================================================ -->
   <!--       rules we'd like to enforce, but haven't cleaned up the codebase yet        -->
   <!-- ================================================================================ -->