added _.keys definition

lodash/lodash-tests.ts

@@ -653,6 +653,8 @@ result = <boolean>_.isString('moe');
 
 result = <boolean>_.isUndefined(void 0);
 
+result = <string[]>_.keys({ 'one': 1, 'two': 2, 'three': 3 });
+
 var mergeNames = {
   'stooges': [
     { 'name': 'moe' },
@@ -696,7 +698,7 @@ _.merge(mergeFood, mergeOtherFood, function(a, b) {
 
 
 
-_.keys({ one: 1, two: 2, three: 3 });
+
 _.values({ one: 1, two: 2, three: 3 });
 _.pairs({ one: 1, two: 2, three: 3 });
 _.pick({ name: 'moe', age: 50, userid: 'moe1' }, 'name', 'age');

lodash/lodash.d.ts

@@ -2495,6 +2495,13 @@ declare module _ {
 	**/
 	export function isUndefined(value: any): boolean;
 
+	/**
+	* Creates an array composed of the own enumerable property names of an object.
+	* @param object The object to inspect.
+	* @return An array of property names.
+	**/
+	export function keys(object: any): string[];
+
 	/**
 	* Recursively merges own enumerable properties of the source object(s), that don't resolve 
 	* to undefined into the destination object. Subsequent sources will overwrite property 
@@ -2650,12 +2657,7 @@ declare module _ {
 	* Objects *
 	***********/
 
-	/**
-	* Retrieve all the names of the object's properties.
-	* @param object Retreive the key or property names from this object.
-	* @return List of all the property names on `object`.
-	**/
-	export function keys(object: any): string[];
+	
 
 	/**
 	* Return all of the values of the object's properties.