Drop support for Ruby 1.9.3

Ruby 1.9.3 reached end-of-life in February 2015. We've kept support
because it wasn't an issue, but we're now seeing issues installing the
`json` gem in our tests.

Bump the minimum Ruby version to 2+ and update documentation
accordingly.

Author: sds

.travis.yml

@@ -5,7 +5,6 @@ sudo: false
 cache: bundler
 
 rvm:
-  - 1.9.3
   - 2.0
   - 2.1
   - 2.2

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Overcommit Changelog
 
+## master (unreleased)
+
+* Drop support for Ruby 1.9.3
+
 ## 0.34.2
 
 * Add `--no-color` flag to all `git diff`/`git show` calls to override local

README.md

@@ -53,13 +53,11 @@ writing any Ruby code.
 
 ## Requirements
 
-This project aims to support the following Ruby runtimes:
+This project aims to support the following Ruby runtimes on both \*nix and Windows:
 
-* MRI 1.9.3 & 2.x
+* MRI 2.x
 * JRuby 1.7.x
 
-Windows is currently supported only for MRI Ruby 2.x
-
 ## Limitations
 
 Overcommit does not currently support

overcommit.gemspec

@@ -24,7 +24,7 @@ Gem::Specification.new do |s|
                             Dir['libexec/**/*'] +
                             Dir['template-dir/**/*']
 
-  s.required_ruby_version = '>= 1.9.3'
+  s.required_ruby_version = '>= 2'
 
   s.add_dependency             'childprocess', '~> 0.5.8'
   s.add_dependency             'iniparse', '~> 1.4'