Cleanup `Makefile`

Makefile

@@ -4,19 +4,35 @@ PREFIX ?= /usr/local
 SHARD_BIN ?= ../../bin
 CRFLAGS ?= -Dpreview_mt
 
-build: bin/ameba
-bin/ameba:
+.PHONY: build
+build:
 	$(SHARDS_BIN) build $(CRFLAGS)
+
+.PHONY: lint
+lint: build
+	./bin/ameba --all
+
+.PHONY: spec
+spec:
+	$(CRYSTAL_BIN) spec
+
+.PHONY: clean
 clean:
 	rm -f ./bin/ameba ./bin/ameba.dwarf
+
+.PHONY: install
 install: build
 	mkdir -p $(PREFIX)/bin
 	cp ./bin/ameba $(PREFIX)/bin
+
+.PHONY: bin
 bin: build
 	mkdir -p $(SHARD_BIN)
 	cp ./bin/ameba $(SHARD_BIN)
+
+.PHONY: run_file
 run_file:
 	cp -n ./bin/ameba.cr $(SHARD_BIN) || true
-test: build
-	$(CRYSTAL_BIN) spec
-	./bin/ameba --all
+
+.PHONY: test
+test: spec lint