Adding ruby version spec to all gemspec files to at least 1.8.7

Signed-off-by: José Valim <jose.valim@gmail.com>

actionmailer/actionmailer.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'Email composition, delivery, and recieval framework (part of Rails).'
   s.description = 'Email composition, delivery, and recieval framework (part of Rails).'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'

actionpack/actionpack.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'Web-flow and rendering framework putting the VC in MVC (part of Rails).'
   s.description = 'Web-flow and rendering framework putting the VC in MVC (part of Rails).'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'

activemodel/activemodel.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version = '3.0.0.beta1'
   s.summary = "A toolkit for building other modeling frameworks like ActiveRecord"
   s.description = %q{Extracts common modeling concerns from ActiveRecord to share between similar frameworks like ActiveResource.}
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author = "David Heinemeier Hansson"
   s.email = "david@loudthinking.com"

activerecord/activerecord.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'Object-relational mapper framework (part of Rails).'
   s.description = 'Object-relational mapper framework (part of Rails).'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'

activeresource/activeresource.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'REST-model framework (part of Rails).'
   s.description = 'REST-model framework (part of Rails).'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'

activesupport/activesupport.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'Support and utility classes used by the Rails framework.'
   s.description = 'Support and utility classes used by the Rails framework.'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'

rails.gemspec

@@ -4,12 +4,13 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'Full-stack web-application framework.'
   s.description = 'Full-stack web-application framework.'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'
   s.homepage          = 'http://www.rubyonrails.org'
   s.rubyforge_project = 'rails'
-
+  
   s.files = []
   s.require_path = []
 

rails3b.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0'
   s.summary     = 'Just the Rails 3 beta dependencies. Works around prerelease RubyGems bug.'
   s.description = 'My kingdom for working dependencies.'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'Jeremy Kemper'
   s.email             = 'jeremy@bitsweat.net'

railties/railties.gemspec

@@ -4,6 +4,7 @@ Gem::Specification.new do |s|
   s.version     = '3.0.0.beta1'
   s.summary     = 'Controls boot-up, rake tasks and generators for the Rails framework.'
   s.description = 'Controls boot-up, rake tasks and generators for the Rails framework.'
+  s.required_ruby_version = '>= 1.8.7'
 
   s.author            = 'David Heinemeier Hansson'
   s.email             = 'david@loudthinking.com'