Fix log level setting logic

lib/util.js

@@ -7,8 +7,9 @@ var util = {
   // Logging logic
   logLevel: 0,
   setLogLevel: function(level) {
-    if (level = parseInt(level, 10)) {
-      util.logLevel = level;
+    var debugLevel = parseInt(level, 10);
+    if (!isNaN(parseInt(level, 10))) {
+      util.logLevel = debugLevel;
     } else {
       // If they are using truthy/falsy values for debug
       util.logLevel = (!!level) ? 3 : 0;