Prevent install failure of childprocess on windows Ruby 2.2.10

Author: benoittgt

Gemfile

@@ -48,7 +48,7 @@ else
   gem 'ffi', '~> 1.11.0'
 end
 
-if RUBY_VERSION < '2.2.0' && !!(RbConfig::CONFIG['host_os'] =~ /cygwin|mswin|mingw|bccwin|wince|emx/)
+if RUBY_VERSION < '2.3.0' && !!(RbConfig::CONFIG['host_os'] =~ /cygwin|mswin|mingw|bccwin|wince|emx/)
   gem "childprocess", "< 1.0.0"
 end