Add Node 16 to CI (#5372)

Author: GeoffreyBooth

.github/workflows/continuous-integration.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest, macos-latest, windows-latest]
-        node-version: [6.x, 8.x, 10.x, 12.x, 14.x]
+        node-version: [6.x, 8.x, 10.x, 12.x, 14.x, 16.x]
 
     steps:
     - uses: actions/checkout@v2
@@ -34,11 +34,11 @@ jobs:
 
     - run: node ./bin/cake test:browser
       if: matrix.node-version != '6.x' && matrix.node-version != '8.x'
-    
+
     - run: node ./bin/cake test:browser:node
 
     - run: node ./bin/cake test:integrations
-    
+
     - run: node ./bin/cake build:except-parser
     - run: node ./bin/cake build:parser
     - run: node ./bin/cake build:full