Replace Makefile with build_posix.sh

Makefile

@@ -1,7 +0,0 @@
-PKGS=glfw3 gl
-CFLAGS=-Wall -Wextra -ggdb -I./include/ `pkg-config --cflags $(PKGS)`
-LIBS=`pkg-config --libs $(PKGS)` -lm
-
-main: main.c
-	$(CC) $(CFLAGS) -o main main.c $(LIBS)
-

build_posix.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+set -xe
+
+CC=cc
+CFLAGS="-Wall -Wextra -ggdb -I./include/"
+LIBS="-lglfw -lGL -lm"
+
+$CC $CFLAGS -o main main.c $LIBS