Disabled failing AppVeyor job for node 8

Author: Simon Hofmann

appveyor.yml

@@ -61,6 +61,10 @@ environment:
       # use self build
       OPENCV4NODEJS_DISABLE_AUTOBUILD: 1
 
+matrix:
+  exclude:
+    - nodejs_version: 8
+
 install:
   - cmd: choco install OpenCV -y -version %OPENCV_VERSION%
   - IF EXIST c:\tools\opencv* CD c:\tools\opencv*