Fixed make install

Makefile

+PREFIX=$(DESTDIR)/usr
+BINDIR=$(PREFIX)/bin
+
 CC=gcc
 CFLAGS=-std=c89 -O2 -pedantic -Wall -I"./include"
 
 exp:
 	$(CC) $(CFLAGS) -E  src/helpers.c src/light.c
 
+install: all
+	mkdir -p $(BINDIR)
+	cp -f ./light $(BINDIR)/light
+	chown root $(BINDIR)/light
+	chmod 4755 $(BINDIR)/light
+
+uninstall:
+	rm $(BINDIR)/light
+	rm -rf /etc/light
+
 clean:
 	rm -vfr *~ light