cleanup the way defines are handled in tests.

examples/temp_sensor/project.yml

@@ -28,7 +28,7 @@
   :executable: '.exe'
 
 :defines:
-  :common:
+  :test:
     - __monitor
     - UNITY_SUPPORT_64
 

examples/temp_sensor/rakefile_helper.rb

@@ -132,7 +132,7 @@ module RakefileHelpers
 
   # All defines: project common + Unity target + CMock overlay + any extras
   def all_defines(extra = [])
-    (($proj[:defines][:common] || []) +
+    (($proj[:defines][:test] || []) +
      ($unity_cfg[:defines][:test] || []) +
      (($cmock_cfg[:defines] || {})[:test] || []) +
      extra).uniq