Allow build artifacts on AppVeyor (#2752)

Enabled the creation of JerryScript Windows binary artifacts during builds.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

Author: galpeter

appveyor.yml

@@ -30,3 +30,7 @@ build:
   project: build\Jerry.sln
   parallel: true
   verbosity: minimal
+
+artifacts:
+  - path: build\bin\$(configuration)\
+    name: JerryScriptBinary