Fix Makefile uninstall target

Author: dhemery

Diff for: Makefile

@@ -18,13 +18,16 @@ include $(RACK_DIR)/plugin.mk
 # Below this line: Targets for Dale to build the gui and run Rack
 
 RACK_APP = /Applications/Rack.app
-RACK_PLUGINS_DIR = ~/Documents/Rack/plugins
+
+RACK_PLUGINS_DIR = $(RACK_USER_DIR)/plugins
+MODULE_INSTALL_DIR = $(RACK_PLUGINS_DIR)/$(SLUG)
+MODULE_INSTALL_ZIP = $(RACK_PLUGINS_DIR)/$(SLUG)-$(VERSION)-$(ARCH).zip
 
 run: install
 	open $(RACK_APP)
 
 uninstall:
-	rm -rf $(MODULE_INSTALL_DIR)
+	rm -rf $(MODULE_INSTALL_DIR) $(MODULE_INSTALL_ZIP)
 
 .PHONY: gui
 gui: