Add tests for uncovered lines

 Add extern UnityFixture in internals header. Add C89 target in Makefile
 clang will show these warnings but can suppress "//" with -Wno-comment.

 Turn on -Wconversion in Makefile, fix all warnings

 Comment out -Wconversion for now, since the build would fail

 This feature removes the dependency on malloc/free for constrained
  embedded systems without a heap. It uses a static heap inside
  Unity Fixture. Setting UNITY_INTERNAL_HEAP_SIZE_BYTES sizes the heap.
 Add tests for new option, add targets to makefile for running tests.
 UNITY_FIXTURE_MALLOC for Fixture use only, remove from unity_output_Spy.c.

 Add CFLAGS in Fixture Makefile to catch C99 rules with '-pedantic'

 No rake and ruby required to build existing tests