remove the system go-bindata requirement.

close #1
close #3

Makefile

@@ -1,5 +1,3 @@
-GO_BINDATA_VERSION = $(shell go-bindata --version | cut -d ' ' -f2 | head -n 1 || echo "missing")
-REQ_GO_BINDATA_VERSION = 3.2.0
 GO ?= go
 
 build:
@@ -8,10 +6,7 @@ build:
 .PHONY: build
 
 bindata:
-ifneq ($(GO_BINDATA_VERSION),$(REQ_GO_BINDATA_VERSION))
-	go get -u github.com/shuLhan/go-bindata/...;
-endif
-	@go-bindata \
+	@$(GO) run vendor/github.com/shuLhan/go-bindata/go-bindata/*.go \
 		-nometadata	\
 		-o internal/bindata/bindata.go -pkg bindata \
 	    data/...;