ensure bin directory gets created

Makefile

@@ -29,7 +29,7 @@ bin/FC_pregmod.html: bin/FC_pregmod_tmp
 	git checkout -- src/gui/mainMenu/AlphaDisclaimer.tw
 	mv $< $@
 
-bin/FC_pregmod_tmp: src/gui/mainMenu/AlphaDisclaimer.tw
+bin/FC_pregmod_tmp: bin/ src/gui/mainMenu/AlphaDisclaimer.tw
 	TWEEGO_PATH=devTools/tweeGo/storyFormats $(TWEEGO) -o $@ src/ --head devTools/head.html
 	./devTools/embed_favicon.py $@
 
@@ -37,6 +37,9 @@ src/gui/mainMenu/AlphaDisclaimer.tw:
 	sed -Ei "s/build .releaseID/\0 commit $(COMMIT)/" $@
 	sed -Ei "s/build .releaseID/\0 commit $(COMMIT)/" $@
 
+bin/:
+	mkdir -p $@
+
 sanity:
 	./sanityCheck.sh