Allow configuration of logLevel (#33)

Allow consumers of the JavaScript SDK to specify the logging level during initialization

Author: delikat

index.js

@@ -21,11 +21,13 @@ module.exports = {
    * @param  {Object} config.errorHandler
    * @param  {Object} config.eventDispatcher
    * @param  {Object} config.logger
+   * @param  {Object} config.logLevel
    * @return {Object} the Optimizely object
    * @throws If any of the config options that were passed in are invalid
    */
   createInstance: function(config) {
-    var defaultLogger = logger.createLogger({ logLevel: enums.LOG_LEVEL.INFO });
+    var logLevel = config.logLevel || enums.LOG_LEVEL.INFO;
+    var defaultLogger = logger.createLogger({ logLevel: logLevel });
     if (config) {
       try {
         configValidator.validate(config);