misc gem and dep maintenance

Gemfile

@@ -6,4 +6,7 @@ source "https://rubygems.org/"
 # Specify your gem's dependencies in einhorn.gemspec
 gemspec
 
-gem "standard", group: [:development, :test]
+group :development, :test do
+  gem "standard"
+  gem "debug"
+end

einhorn.gemspec

@@ -23,6 +23,6 @@ Gem::Specification.new do |gem|
 
   gem.add_development_dependency "rake", "~> 13"
   gem.add_development_dependency "minitest", "~> 5"
-  gem.add_development_dependency "mocha", "~> 1"
+  gem.add_development_dependency "mocha", "~> 2"
   gem.add_development_dependency "subprocess", "~> 1"
 end

test/_lib.rb

@@ -5,7 +5,7 @@
 require "minitest/spec"
 require "mocha/minitest"
 
-class EinhornTestCase < ::MiniTest::Spec
+class EinhornTestCase < ::Minitest::Spec
   def setup
     # Put global stubs here
   end

test/integration/_lib/helpers/einhorn_helpers.rb

@@ -10,7 +10,7 @@ def einhorn_code_dir
 
     def default_einhorn_command
       cmd = ["bundle", "exec"]
-      cmd << "--keep-file-descriptors" if RUBY_VERSION >= "2.0"
+      cmd << "--keep-file-descriptors"
       cmd << File.expand_path("bin/einhorn", einhorn_code_dir)
 
       cmd
@@ -125,7 +125,7 @@ def wait_for_open_port
     end
 
     def read_from_port
-      ewouldblock = (RUBY_VERSION >= "1.9.0") ? IO::WaitWritable : Errno::EINPROGRESS
+      ewouldblock = IO::WaitWritable
       socket = Socket.new(Socket::PF_INET, Socket::SOCK_STREAM, 0)
       sockaddr = Socket.pack_sockaddr_in(@port, "127.0.0.1")
       begin