Drop support of Ruby < 2.2 (#481)

.travis.yml

 sudo: false
 language: ruby
 rvm:
-  - 1.9.3
-  - 2.0
-  - 2.1
   - 2.2.5
   - 2.3.0
   - 2.4.0
@@ -11,7 +8,6 @@ rvm:
 matrix:
   allow_failures:
     - rvm: ruby-head
-    - rvm: 1.9.3
 before_install:
   - gem update --system
   - gem update bundler

Gemfile

 source 'https://rubygems.org'
 
+ruby '>= 2.2.0'
+
 gem 'activerecord', '>= 4.2.5', require: false
 gem 'rake', require: false
 

annotate.gemspec

@@ -7,7 +7,7 @@ Gem::Specification.new do |s|
   s.name = 'annotate'
   s.version = Annotate.version
 
-  s.required_ruby_version = '>= 1.9.3'
+  s.required_ruby_version = '>= 2.2.0'
   s.required_rubygems_version = Gem::Requirement.new('>= 0') if s.respond_to? :required_rubygems_version=
   s.authors = ['Alex Chaffee', 'Cuong Tran', 'Marcos Piccinini', 'Turadg Aleahmad', 'Jon Frisby']
   s.description = 'Annotates Rails/ActiveRecord Models, routes, fixtures, and others based on the database schema.'