Gemfile in helio-ruby-0.3.0 vs Gemfile in helio-ruby-0.3.1

@@ -2,11 +2,11 @@
 
 gemspec
 
 group :development do
   gem "coveralls", require: false
-  gem "mocha", "~> 1.7.0"
+  gem "mocha", "~> 1.8.0"
   gem "rake"
   gem "shoulda-context"
   gem "test-unit"
   gem "timecop"
   gem "webmock"
@@ -15,18 +15,10 @@
   # names or go into new namespaces. This is a library and we don't have
   # `Gemfile.lock` checked in, so to prevent good builds from suddenly going
   # bad, pin to a specific version number here. Try to keep this relatively
   # up-to-date, but it's not the end of the world if it's not.
   gem "rubocop", "0.50.0"
-
-  # Rack 2.0+ requires Ruby >= 2.2.2 which is problematic for the test suite on
-  # older Ruby versions. Check Ruby the version here and put a maximum
-  # constraint on Rack if necessary.
-  if RUBY_VERSION >= "2.2.2"
-    gem "rack", ">= 1.5"
-  else
-    gem "rack", ">= 1.5", "< 2.0" # rubocop:disable Bundler/DuplicatedGem
-  end
+  gem "rack", ">= 2.0.8"
 
   platforms :mri do
     # to avoid problems, bring Byebug in on just versions of Ruby under which
     # it's known to work well
     if Gem::Version.new(RUBY_VERSION.dup) >= Gem::Version.new("2.0.0")