Added ability to inject defines, much like what was built into Ceedling before...

Added ability to inject defines, much like what was built into Ceedling before Ceedling switched to just using this generator.

auto/generate_test_runner.rb

@@ -23,6 +23,7 @@ class UnityTestRunnerGenerator
   def self.default_options
     {
       :includes         => [],
+      :defines          => [],
       :plugins          => [],
       :framework        => :unity,
       :test_prefix      => "test|spec|should",
@@ -167,6 +168,9 @@ class UnityTestRunnerGenerator
     output.puts('#include <setjmp.h>')
     output.puts('#include <stdio.h>')
     output.puts('#include "CException.h"') if @options[:plugins].include?(:cexception)
+    if (@options[:defines] && !@options[:defines].empty?)
+      @options[:defines].each {|d| output.puts("#define #{d}")}
+    end
     if (@options[:header_file] && !@options[:header_file].empty?)
       output.puts("#include \"#{File.basename(@options[:header_file])}\"")
     else