title: Error Installing Spree in a Rails Project
body: <p>I get the error below when trying to install Spree within a new Rails project.  I have Rails version 4.2.5 installed, and Ruby version 2.3.0p0</p>
  
  <pre><code>$ spree install --auto-accept
  [WARNING] Spree CMD Installer is deprecated. Please follow installation     instructions at https://github.com/spree/spree#getting-started
  /usr/local/rvm/rubies/ruby-    2.3.0/lib/ruby/2.3.0/rubygems/specification.rb:2158:in `method_missing':     undefined method `this' for #&lt;Gem::Specification:0x3fcb12418c74     activesupport-5.0.0.1&gt; (NoMethodError)
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/specification.rb:1057:in `find_active_stub_by_path'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:64:in `require'
  from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/core_ext/string.rb:1:in `&lt;top (required)&gt;'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `require'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `rescue in require'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:40:in `require'
  from /usr/local/rvm/gems/ruby-2.3.0/gems/spree_cmd-3.1.1/lib/spree_cmd/installer.rb:2:in `&lt;top (required)&gt;'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
  from /usr/local/rvm/gems/ruby-2.3.0/gems/spree_cmd-3.1.1/lib/spree_cmd.rb:14:in `&lt;top (required)&gt;'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
  from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
  from /usr/local/rvm/gems/ruby-2.3.0/gems/spree_cmd-3.1.1/bin/spree:2:in `&lt;top (required)&gt;'
  from /usr/local/rvm/gems/ruby-2.3.0/bin/spree:23:in `load'
  from /usr/local/rvm/gems/ruby-2.3.0/bin/spree:23:in `&lt;main&gt;'
  from /usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval'
  from /usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `&lt;main&gt;'`
  </code></pre>