Dropping official support for Ruby < 2.2.2.

Author: djanowski

.travis.yml

@@ -3,8 +3,7 @@ language: ruby
 script: make test
 
 rvm:
-  - 2.1
-  - 2.2
+  - 2.2.2
   - 2.3.3
   - 2.4.1
   - jruby-9

CHANGELOG.md

@@ -7,6 +7,8 @@
 * Added support for `CLIENT` commands. The lower-level client can be
   accessed via `Redis#_client`.
 
+* Dropped official support for Ruby < 2.2.2.
+
 # 3.3.3
 
 * Improved timeout handling after dropping Timeout module.

redis.gemspec

@@ -34,6 +34,8 @@ Gem::Specification.new do |s|
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
 
+  s.required_ruby_version = '>= 2.2.2'
+
   s.add_development_dependency("test-unit", ">= 3.1.5")
   s.add_development_dependency("hiredis")
   s.add_development_dependency("em-synchrony")