Updated the Rake dependency to 11.1

In 599b295, the Rake dependency has been pinned to < 11, but that prevents installing
of gems depending on later versions. The offending `last_comment` method was restored in Rake 11.1,
so it is safe to pin that version (relaxed). Furthermore, a patch to Yard is coming up which
fixes the original problem there.

Thanks for reporting and all the pointers, @dominicsayers!

Closes elastic#566

Related: lsegal/yard#964

Author: karmi

Gemfile

@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 gem "bundler", "~> 1"
-gem "rake", "< 11.0"
+gem "rake", "~> 11.1"
 
 gem 'elasticsearch'
 gem 'elasticsearch-extensions'

elasticsearch-model/elasticsearch-model.gemspec

@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
   s.add_dependency "hashie"
 
   s.add_development_dependency "bundler", "~> 1.3"
-  s.add_development_dependency "rake", "< 11.0"
+  s.add_development_dependency "rake", "~> 11.1"
 
   s.add_development_dependency "elasticsearch-extensions"
 

elasticsearch-persistence/elasticsearch-persistence.gemspec

@@ -31,7 +31,7 @@ Gem::Specification.new do |s|
   s.add_dependency "virtus"
 
   s.add_development_dependency "bundler", "~> 1.5"
-  s.add_development_dependency "rake", "< 11.0"
+  s.add_development_dependency "rake", "~> 11.1"
 
   s.add_development_dependency "oj"
 

elasticsearch-rails/elasticsearch-rails.gemspec

@@ -24,7 +24,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = ">= 1.9.3"
 
   s.add_development_dependency "bundler", "~> 1.3"
-  s.add_development_dependency "rake", "< 11.0"
+  s.add_development_dependency "rake", "~> 11.1"
 
   s.add_development_dependency "elasticsearch-extensions"
   s.add_development_dependency "elasticsearch-model"