Prevent array type being picked up as missing class

The `@return Array` typehint was being picked up as a missing class `Fusonic\Linq\Array`, so changed to lower-case.

src/Fusonic/Linq/Linq.php

@@ -681,7 +681,7 @@ private function getLast($func, $throw)
      * @param callable $keySelector     a func that returns the array-key for each element.
      * @param callable $valueSelector   a func that returns the array-value for each element.
      *
-     * @return Array    An array with all values.
+     * @return array    An array with all values.
      */
     public function toArray(callable $keySelector = null, callable $valueSelector = null)
     {
@@ -709,4 +709,4 @@ public function getIterator()
     {
         return $this->iterator;
     }
-}
+}