test(appveyor): remove testing on node 0.10 and 0.12

.appveyor.yml

@@ -7,10 +7,6 @@
 # What combinations to test
 environment:
   matrix:
-    - nodejs_version: "0.10"
-      platform: x86
-    - nodejs_version: "0.12"
-      platform: x86
     - nodejs_version: "4"
       platform: x64
     - nodejs_version: "4"