Stop testing Node 4 on Windows

Author: jscheid

appveyor.yml

@@ -1,21 +1,6 @@
 # Test against this version of Node.js
 environment:
   matrix:
-    - nodejs_version: 4
-      WEBPACK_SUFFIX: '@1'
-      ETWP_SUFFIX: '@1'
-      FL_SUFFIX: '@0'
-      HWP_SUFFIX: '@2'
-    - nodejs_version: 4
-      WEBPACK_SUFFIX: '@2'
-      ETWP_SUFFIX: '@2'
-      FL_SUFFIX: '@1'
-      HWP_SUFFIX: '@2'
-    - nodejs_version: 4
-      WEBPACK_SUFFIX: '@3'
-      ETWP_SUFFIX: '@3'
-      FL_SUFFIX: '@1'
-      HWP_SUFFIX: '@2'
     - nodejs_version: 6
       WEBPACK_SUFFIX: '@1'
       ETWP_SUFFIX: '@1'