fixed retry() and forever (#76)

* fixed retry()

* fixed forever

* Update package.json

Author: wizo06

lib/retry_operation.js

@@ -25,7 +25,7 @@ module.exports = RetryOperation;
 
 RetryOperation.prototype.reset = function() {
   this._attempts = 1;
-  this._timeouts = this._originalTimeouts;
+  this._timeouts = this._originalTimeouts.slice(0);
 }
 
 RetryOperation.prototype.stop = function() {
@@ -62,8 +62,7 @@ RetryOperation.prototype.retry = function(err) {
     if (this._cachedTimeouts) {
       // retry forever, only keep last error
       this._errors.splice(0, this._errors.length - 1);
-      this._timeouts = this._cachedTimeouts.slice(0);
-      timeout = this._timeouts.shift();
+      timeout = this._cachedTimeouts.slice(-1);
     } else {
       return false;
     }

package.json

@@ -13,7 +13,7 @@
   "directories": {
     "lib": "./lib"
   },
-  "main": "index",
+  "main": "index.js",
   "engines": {
     "node": ">= 4"
   },