Extract cucumber env and steps to ease code reuse

producer extensions like producer-rails must not reimplement all the
testing infrastructure, this extraction allows to setup everything with
just one require call in cucumber env:

    require 'producer/core/testing/cucumber'

features/support/env.rb

@@ -1,51 +1 @@
-require 'aruba/cucumber'
+require 'producer/core/testing/cucumber'
-require 'aruba/in_process'
-require 'producer/core'
-
-class ArubaProgramWrapper
-  def initialize(argv, stdin = $stdin, stdout = $stdout, stderr = $stderr,
-    kernel = Kernel)
-    @argv   = argv
-    @stdin  = stdin
-    @stdout = stdout
-    @stderr = stderr
-    @kernel = kernel
-  end
-
-  def execute!
-    Producer::Core::CLI.run!(
-      @argv.dup, stdin: @stdin, stdout: @stdout, stderr: @stderr
-    )
-  rescue SystemExit => e
-    @kernel.exit e.status
-  end
-end
-
-
-# Raise aruba default timeout so test suite can run on a slow machine.
-Before do
-  @aruba_timeout_seconds = 8
-end
-
-# Use aruba "in process" optimization only for scenarios not tagged @exec.
-# We need a real process in a few cases: real program name, interactive usage…
-Before('@exec') do
-  Aruba.process = Aruba::SpawnProcess
-end
-
-Before('~@exec') do
-  Aruba::InProcess.main_class = ArubaProgramWrapper
-  Aruba.process = Aruba::InProcess
-end
-
-# Fake home directory for @fake_home tagged scenarios.
-Before('@fake_home') do
-  ENV['HOME'] = File.expand_path(current_dir)
-end
-
-# Enable cucumber-sshd "fast" mode (persists sshd across scenarios), and
-# register hooks for @sshd tagged scenarios.
-Before do
-  @_sshd_fast = true
-end
-require 'cucumber/sshd/cucumber'

lib/producer/core/testing/aruba_program_wrapper.rb

@@ -0,0 +1,24 @@
+module Producer
+  module Core
+    module Testing
+      class ArubaProgramWrapper
+        def initialize(argv, stdin = $stdin, stdout = $stdout, stderr = $stderr,
+          kernel = Kernel)
+          @argv   = argv
+          @stdin  = stdin
+          @stdout = stdout
+          @stderr = stderr
+          @kernel = kernel
+        end
+
+        def execute!
+          Producer::Core::CLI.run!(
+            @argv.dup, stdin: @stdin, stdout: @stdout, stderr: @stderr
+          )
+        rescue SystemExit => e
+          @kernel.exit e.status
+        end
+      end
+    end
+  end
+end

lib/producer/core/testing/cucumber.rb

@@ -0,0 +1,39 @@
+require 'aruba/cucumber'
+require 'aruba/in_process'
+
+require 'producer/core'
+require 'producer/core/testing/aruba_program_wrapper'
+require 'producer/core/testing/cucumber/etc_steps'
+require 'producer/core/testing/cucumber/execution_steps'
+require 'producer/core/testing/cucumber/output_steps'
+require 'producer/core/testing/cucumber/recipe_steps'
+require 'producer/core/testing/cucumber/remote_steps'
+require 'producer/core/testing/cucumber/ssh_steps'
+
+# Raise aruba default timeout so test suite can run on a slow machine.
+Before do
+  @aruba_timeout_seconds = 8
+end
+
+# Use aruba "in process" optimization only for scenarios not tagged @exec.
+# We need a real process in a few cases: real program name, interactive usage…
+Before('@exec') do
+  Aruba.process = Aruba::SpawnProcess
+end
+
+Before('~@exec') do
+  Aruba::InProcess.main_class = Producer::Core::Testing::ArubaProgramWrapper
+  Aruba.process = Aruba::InProcess
+end
+
+# Fake home directory for @fake_home tagged scenarios.
+Before('@fake_home') do
+  ENV['HOME'] = File.expand_path(current_dir)
+end
+
+# Enable cucumber-sshd "fast" mode (persists sshd across scenarios), and
+# register hooks for @sshd tagged scenarios.
+Before do
+  @_sshd_fast = true
+end
+require 'cucumber/sshd/cucumber'