Add Node.js 12 to CI Services (#68)

* Add Node.js 12 to CI Services

* TMP: Allow Node.js 12 Failure on AppVeyor
diff --git a/.travis.yml b/.travis.yml
index ec4c0ad..2361f5d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,9 +5,10 @@
   depth: 10
 
 node_js:
-  - "6"
-  - "8"
-  - "10"
+  - 6
+  - 8
+  - 10
+  - 12
 
 install:
   - npm install
diff --git a/appveyor.yml b/appveyor.yml
index f34dfbd..1d4c45c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,11 +1,18 @@
 # appveyor file
 # http://www.appveyor.com/docs/appveyor-yml
 
+shallow_clone: true
+
 environment:
   matrix:
-  - nodejs_version: "6"
-  - nodejs_version: "8"
-  - nodejs_version: "10"
+  - nodejs_version: 6
+  - nodejs_version: 8
+  - nodejs_version: 10
+  - nodejs_version: 12
+
+matrix:
+  allow_failures:
+    - nodejs_version: 12
 
 install:
   - ps: Install-Product node $env:nodejs_version