Only activate unittest in test builds

makefile

@@ -1,6 +1,6 @@
 SRC := $(shell find src -name "*.d") $(shell find libdparse/src -name "*.d")
 INCLUDE_PATHS := -Ilibdparse/src
-DMD_FLAGS := -g -w -unittest $(INCLUDE_PATHS)
+DMD_FLAGS := -g -w $(INCLUDE_PATHS)
 LDC_FLAGS := -g -w -oq $(INCLUDE_PATHS)
 
 .PHONY: dmd ldc test
@@ -11,9 +11,9 @@ ldc: $(SRC)
 	ldc2 $(LDC_FLAGS) $(SRC) -ofbin/dfmt
 	-rm -f *.o
 
-test: bin/dfmt
+test:
+	dmd $(DMD_FLAGS) -unittest $(SRC) -ofbin/dfmt
 	cd tests && ./test.sh
 
 bin/dfmt: $(SRC)
 	dmd $(DMD_FLAGS) $(SRC) -ofbin/dfmt
-