WIP: Enable parallel_spec

wip:
* [ ] Update README

setup:

* bundle
* rake parallel:create (to setup test databases)

usage:
RAILS_ENV=test rake parallel:spec (without spring)
bin/parallel_rspec spec (with spring)

timing on my slow macbook:
> rake spec
Finished in 55.08 seconds (files took 6.85 seconds to load)
> RAILS_ENV=test rake parallel:spec
Took 47 seconds

.rspec_parallel

@@ -0,0 +1,2 @@
+--format progress
+--format ParallelTests::RSpec::RuntimeLogger --out tmp/parallel_runtime_rspec.log

Gemfile

@@ -83,6 +83,8 @@ group :development, :test do
   gem 'faker'
   gem 'rspec-rails'
   gem 'rspec_junit_formatter', require: false
+  gem 'parallel_tests'
+  gem 'spring-commands-parallel-tests'
   gem "dotenv-rails"
   gem "debase"
 end

Gemfile.lock

@@ -304,6 +304,8 @@ GEM
       mini_portile2 (~> 2.4.0)
     orm_adapter (0.5.0)
     parallel (1.19.1)
+    parallel_tests (2.32.0)
+      parallel
     parser (2.7.1.0)
       ast (~> 2.4.0)
     pg (1.2.3)
@@ -447,6 +449,8 @@ GEM
     shoulda-matchers (4.3.0)
       activesupport (>= 4.2.0)
     spring (2.1.0)
+    spring-commands-parallel-tests (1.0.1)
+      spring (>= 0.9.1)
     spring-commands-rspec (1.0.4)
       spring (>= 0.9.1)
     spring-watcher-listen (2.0.1)
@@ -545,6 +549,7 @@ DEPENDENCIES
   listen
   mailjet
   metamagic
+  parallel_tests
   pg
   premailer-rails
   puma
@@ -567,6 +572,7 @@ DEPENDENCIES
   sentry-raven
   shoulda-matchers
   spring
+  spring-commands-parallel-tests
   spring-commands-rspec
   spring-watcher-listen
   therubyracer

bin/parallel_rspec

@@ -0,0 +1,8 @@
+#!/usr/bin/env ruby
+begin
+  load File.expand_path('spring', __dir__)
+rescue LoadError => e
+  raise unless e.message.include?('spring')
+end
+require 'bundler/setup'
+load Gem.bin_path('parallel_tests', 'parallel_rspec')

bin/spring

@@ -1,14 +1,14 @@
 #!/usr/bin/env ruby
 
-# This file loads spring without using Bundler, in order to be fast.
+# This file loads Spring without using Bundler, in order to be fast.
 # It gets overwritten when you run the `spring binstub` command.
 
 unless defined?(Spring)
   require 'rubygems'
   require 'bundler'
 
   lockfile = Bundler::LockfileParser.new(Bundler.default_lockfile.read)
-  spring = lockfile.specs.detect { |spec| spec.name == "spring" }
+  spring = lockfile.specs.detect { |spec| spec.name == 'spring' }
   if spring
     Gem.use_paths Gem.dir, Bundler.bundle_path.to_s, *Gem.path
     gem 'spring', spring.version