disable 2.0 and 2.1 builds

.travis.yml

@@ -3,8 +3,6 @@ language: ruby
 sudo: false # taking advantage of container-based infrastructure
 cache: bundler # cache bundled gems from build to build
 rvm:
-  - 2.0
-  - 2.1
   - 2.2
   - 2.3.0
 matrix:

appveyor.yml

@@ -4,10 +4,6 @@ skip_tags: true
 
 environment:
   matrix:
-    - ruby_version: "200"
-    - ruby_version: "200-x64"
-    - ruby_version: "21"
-    - ruby_version: "21-x64"
     - ruby_version: "22"
     - ruby_version: "22-x64"