better makefile

src/makefile

@@ -1,7 +1,8 @@
 CXX         := g++
 CXXFLAGS    := -std=c++14 -Wall
 
-OBJECTS     := main.o Parser.o Optimizer.o
+SOURCES     := $(wildcard *.cpp)
+OBJECTS     := $(patsubst %.cpp, %.o, $(SOURCES))
 EXECUTABLE  := zombie
 
 all: $(EXECUTABLE)