Changed Darwin platofrm build options

* Swapped out `dylib` extension for `bundle`
* Changed build flags to use just the `-bundle` flag

Author: James Thompson

.gitignore

@@ -10,4 +10,5 @@
 /vendor
 /ext/argon2_wrap/libargon2_wrap.so
 /ext/argon2_wrap/tests
+/ext/argon2_wrap/libargon2_wrap.bundle*
 argon2-0.0.2.gem

ext/argon2_wrap/Makefile

@@ -35,8 +35,8 @@ ifeq ($(KERNEL_NAME), NetBSD)
 	LIB_CFLAGS := -shared -fPIC
 endif
 ifeq ($(KERNEL_NAME), Darwin)
-	LIB_EXT := dylib
-	LIB_CFLAGS := -dynamiclib -install_name @rpath/lib$(LIB_NAME).$(LIB_EXT)
+	LIB_EXT := bundle
+	LIB_CFLAGS := -bundle
 endif
 ifeq ($(findstring MINGW, $(KERNEL_NAME)), MINGW)
 	LIB_EXT := dll