revert: pin Node.js 10.x version to 10.0.0 …

This finisheds the revert of  commit a36e257 and configures AppVeyor CI
to use the latest Node.js 10.x version, since the problem we were
experiencing in 10.1.0 has been fixed in 10.2.0.

appveyor.yml

@@ -1,7 +1,7 @@
 environment:
   matrix:
     - nodejs_version: "8"
-    - nodejs_version: "10.0.0"
+    - nodejs_version: "10"
 
 install:
   - ps: Install-Product node $env:nodejs_version