Add: fuubar_auto_refresh Configuration Option

Why This Change Is Necessary
========================================================================

When using things like byebug and pry, stopping the execution for
debugging means that you'll also want to stop the bar from refreshing so
that you don't end up with bars all over the screen.

How These Changes Address the Issue
========================================================================

Add a fuubar_auto_refresh RSpec configuration setting which, if set to
`false`, will disable the refresh.

Side Effects Caused By This Change
========================================================================

None known.

------------------------------------------------------------------------
Actions:
  * Closes #105

lib/fuubar.rb

@@ -6,6 +6,16 @@
 require 'fuubar/output'
 
 RSpec.configuration.add_setting :fuubar_progress_bar_options, :default => {}
+RSpec.configuration.add_setting :fuubar_auto_refresh,         :default => true
+
+if Object.const_defined?('Pry')
+  Pry.
+    config.
+    hooks.
+    add_hook(:when_started, :fuubar_kill_refresh) do |_target, _opt, _|
+      RSpec.configuration.fuubar_auto_refresh = false
+    end
+end
 
 class Fuubar < RSpec::Core::Formatters::BaseTextFormatter
   DEFAULT_PROGRESS_BAR_OPTIONS = { :format => ' %c/%C |%w>%i| %e ' }.freeze
@@ -51,16 +61,15 @@ def start(notification)
     self.passed_count        = 0
     self.pending_count       = 0
     self.failed_count        = 0
-    self.example_tick_thread = start_tick_thread(notification)
-
-    if Object.const_defined?('Pry')
-      Pry.
-        config.
-        hooks.
-        add_hook(:when_started, :fuubar_kill_refresh) do |_target, _opt, _|
-          example_tick_thread.kill
-        end
-    end
+    self.example_tick_thread = Thread.new do
+                                 loop do
+                                   sleep(1)
+
+                                   if configuration.fuubar_auto_refresh
+                                     example_tick(notification)
+                                   end
+                                 end
+                               end # rubocop:disable Layout/BlockAlignment
 
     super
 
@@ -163,14 +172,4 @@ def continuous_integration?
     @continuous_integration ||= \
       ![nil, '', 'false'].include?(ENV['CONTINUOUS_INTEGRATION'])
   end
-
-  def start_tick_thread(notification)
-    Thread.new do
-      loop do
-        sleep(1)
-
-        example_tick(notification)
-      end
-    end
-  end
 end