Clean up conversion warnings in Fixture

Turn on -Wconversion in Makefile, fix all warnings

extras/fixture/test/Makefile

@@ -46,7 +46,7 @@ clean:
 # These extended flags DO get included before any target build runs
 CFLAGS += -Wbad-function-cast
 CFLAGS += -Wcast-qual
-#CFLAGS += -Wconversion
+CFLAGS += -Wconversion
 CFLAGS += -Wformat=2
 CFLAGS += -Wmissing-prototypes
 CFLAGS += -Wold-style-definition

extras/fixture/test/unity_fixture_Test.c

@@ -144,7 +144,7 @@ TEST(UnityFixture, FreeNULLSafety)
 TEST_GROUP(UnityCommandOptions);
 
 int savedVerbose;
-int savedRepeat;
+unsigned int savedRepeat;
 const char* savedName;
 const char* savedGroup;
 

extras/fixture/test/unity_output_Spy.c

@@ -22,7 +22,7 @@ void UnityOutputCharSpy_Create(int s)
     size = s;
     count = 0;
     spy_enable = 0;
-    buffer = malloc(size);
+    buffer = malloc((size_t)size);
     TEST_ASSERT_NOT_NULL_MESSAGE(buffer, "Internal malloc failed in Spy Create():" __FILE__);
     memset(buffer, 0, size);
 }
@@ -38,7 +38,7 @@ int UnityOutputCharSpy_OutputChar(int c)
     if (spy_enable)
     {
         if (count < (size-1))
-            buffer[count++] = c;
+            buffer[count++] = (char)c;
     }
     else
     {