ci: add node-14.x to workflow (#88)

diff --git a/.appveyor.yml b/.appveyor.yml
index 6a3c939..ccb9fed 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -15,6 +15,7 @@
   matrix:
     - nodejs_version: "10"
     - nodejs_version: "12"
+    - nodejs_version: "14"
 
 platform:
   - x86
diff --git a/.travis.yml b/.travis.yml
index 145ed33..aeebd0c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,7 +17,7 @@
     - ANDROID_BUILD_TOOLS_VERSION=29.0.2
 
 language: node_js
-node_js: 12
+node_js: 14
 
 # yaml anchor/alias: https://medium.com/@tommyvn/travis-yml-dry-with-anchors-8b6a3ac1b027