Fix issue sndyuk#9: ReferenceError: newClassMap is not defined

Author: sndyuk

lib/optimizer.js

@@ -5,10 +5,10 @@ const ClassGenerator = require('./classGenerator');
 const classGenerator = new ClassGenerator()
 
 const validate = (opts) => {
-  if (opts.log) return;
-  for (let className in newClassMap) {
-    const c = newClassMap[className];
-    if (c.usedBy.length > 1) {
+  if (!opts.log) return;
+  for (let className in classGenerator.newClassMap) {
+    const c = classGenerator.newClassMap[className];
+    if (c.usedBy.length >= 1) {
       continue;
     }
     if (c.usedBy[0].match(/.+\.css:*$/)) {