Project Makefile problems with Google Test

For the life of me I caot figure out how to remove the mv statements in the following makefile

TEST_DIR = ../gtest
USER_DIR = src
TESTS_DIR = tests
OBJ_DIR = obj

CPPFLAGS += -isystem $(GTEST_DIR)/include -I$(USER_DIR)

CXXFLAGS += -g -Wall -Wextra

TESTS = test

GTEST_HEADERS = $(GTEST_DIR)/include/gtest/*.h 
                $(GTEST_DIR)/include/gtest/inteal/*.h

all : $(TESTS)

clean :
    rm -rf obj
    rm -rf bin
    mkdir obj
    mkdir bin

GTEST_SRCS_ = $(GTEST_DIR)/src/*.cc $(GTEST_DIR)/src/*.h $(GTEST_HEADERS)

$(OBJ_DIR)/gtest-all.o : $(GTEST_SRCS_)
    $(CXX) $(CPPFLAGS) -I$(GTEST_DIR) $(CXXFLAGS) -c 
            $(GTEST_DIR)/src/gtest-all.cc
    mv gtest-all.o obj/gtest-all.o

$(OBJ_DIR)/gtest_main.o : $(GTEST_SRCS_)
    $(CXX) $(CPPFLAGS) -I$(GTEST_DIR) $(CXXFLAGS) -c 
            $(GTEST_DIR)/src/gtest_main.cc
    mv gtest_main.o obj/gtest_main.o

$(OBJ_DIR)/gtest.a : $(OBJ_DIR)/gtest-all.o
    $(AR) $(ARFLAGS) $@ $^ 

$(OBJ_DIR)/gtest_main.a : $(OBJ_DIR)/gtest-all.o $(OBJ_DIR)/gtest_main.o
    $(AR) $(ARFLAGS) $@ $^

$(OBJ_DIR)/addition.o : $(USER_DIR)/addition.cpp $(USER_DIR)/addition.h $(GTEST_HEADERS)
    $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< 
    mv addition.o obj/addition.o

$(OBJ_DIR)/test.o : $(TESTS_DIR)/test.cpp $(USER_DIR)/addition.h $(GTEST_HEADERS)
    $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $(TESTS_DIR)/test.cpp 
    mv test.o obj/test.o

test : $(OBJ_DIR)/addition.o $(OBJ_DIR)/test.o $(OBJ_DIR)/gtest_main.a
    $(CXX) $(CPPFLAGS) $(CXXFLAGS) -lpthread $^ -o $@

The problem is the mv test.o obj/test.o line and the others like it. I know there is a way to have make do this automatically for you but for the life of me I caot find/figure it out.

This is the precaed makefile that comes with google test that I have modified to work for me.