Merge pull request #40 from markowsiak/master

Drop Node 6 support, and Babel as a result

Author: jkrems

.babelrc

@@ -1,3 +1,3 @@
 {
-  "extends": "groupon/node6"
+  "extends": "groupon/node8"
 }

.eslintrc

@@ -1,5 +1,4 @@
-/yarn.lock
-/package-lock.json
+/.nyc_output
 node_modules/
 npm-debug.log
 /tmp

.gitignore

@@ -1,8 +1,7 @@
 language: node_js
 node_js:
-  - v6.14.3
-  - v8.11.3
-  - v10.5.0
+  - 8.11.3
+  - 10.5.0
 deploy:
   - provider: script
     script: ./node_modules/.bin/nlm release
@@ -11,3 +10,5 @@ deploy:
       branch: master
       node: 10.5.0
 services: memcached
+before_install:
+  - npm i -g npm@^6

.travis.yml

@@ -76,6 +76,7 @@ Cache.prototype.end = function end() {
   if (this.backend && this.backend.end) {
     return this.backend.end();
   }
+  return null;
 };
 
 Cache.prototype.prepareOptions = function prepareOptions(options) {