Remove node 6 from tested versions

mAAdhaTTah · mAAdhaTTah · commit 209963dfa6c3 · 2019-12-15T18:52:58.000-05:00
This is EOL now.
diff --git a/.travis.yml b/.travis.yml
@@ -3,7 +3,6 @@ before_install:
   - npm i -g npm
 
 node_js:
-  - 6
   - 8
   - 10
   - 12
