.travis.yml in guard-falcon-0.6.0 vs .travis.yml in guard-falcon-0.7.0

@@ -1,14 +1,13 @@
 language: ruby
 sudo: false
 dist: trusty
 cache: bundler
 rvm:
-  - 2.0
-  - 2.1
   - 2.2
   - 2.3
   - 2.4
+  - 2.5
   - jruby-head
   - ruby-head
   - rbx-3
 matrix:
   allow_failures: