update phpexcel

Author: toyi

composer.json

@@ -35,10 +35,7 @@
     "tijsverkoyen/css-to-inline-styles": "~2.0"
   },
   "require-dev": {
-    "phpseclib/phpseclib": "~1.0",
-    "phpunit/phpunit": "~4.0",
-    "mockery/mockery": "~1.0",
-    "orchestra/testbench": "3.1.*|3.2.*|3.3.*|3.4.*|3.5.*|3.6.*"
+    "phpseclib/phpseclib": "~1.0"
   },
   "suggest": {
     "illuminate/http": "^5.0",