Use git tag for app vsn

Makefile

@@ -2,7 +2,6 @@
 
 PROJECT = emqx
 PROJECT_DESCRIPTION = EMQ X Broker
-PROJECT_VERSION = 3.0.0
 
 DEPS = jsx gproc gen_rpc ekka esockd cowboy clique
 

erlang.mk

@@ -1186,7 +1186,7 @@ else
 	fi
 	$(appsrc_verbose) cat src/$(PROJECT).app.src \
 		| sed "s/{[[:space:]]*modules[[:space:]]*,[[:space:]]*\[\]}/{modules, \[$(call comma_list,$(MODULES))\]}/" \
-		| sed "s/{id,[[:space:]]*\"git\"}/{id, \"$(subst /,\/,$(GITDESCRIBE))\"}/" \
+		| sed "s/{vsn,[[:space:]]*\"git\"}/{vsn, \"$(subst /,\/,$(GITDESCRIBE))\"}/" \
 		> ebin/$(PROJECT).app
 endif
 

src/emqx.app.src

@@ -1,6 +1,6 @@
 {application,emqx,
              [{description,"EMQ X Broker"},
-              {vsn,"3.0.0"},
+              {vsn,"git"},
               {modules,[]},
               {registered,[emqx_sup]},
               {applications,[kernel,stdlib,jsx,gproc,gen_rpc,esockd,