Add clean target in testers Makefile

@@ -11,11 +11,11 @@ LIBS = $(TRLIBS) \
        -lrt \
        -luuid
 
-PROHRAMS = testserver2 \
+PROGRAMS = testserver2 \
 	   testtcp \
 	   testudp
 
-all: $(PROHRAMS)
+all: $(PROGRAMS)
 
 testserver2: testserver2.o test_handler.o
 	$(CC) $(LDFLAGS) -std=c99 $(LIBS) -o $@ $< test_handler.o
@@ -31,3 +31,7 @@ testudp.o: testclient.c
 
 %.o: %.c
 	$(CC) $(CFLAGS) -std=c99 -c -o $@ $<
+
+.PHONY: clean
+clean:
+	@rm -Rf *.o $(PROGRAMS)