feat: add version command (#26)

Makefile

@@ -1,13 +1,19 @@
 GO := go
 BIN_DIR := bin
 BIN := $(BIN_DIR)/pmg
+SHELL := /bin/bash
+GITCOMMIT := $(shell git rev-parse HEAD)
+VERSION := "$(shell git describe --tags --abbrev=0)-$(shell git rev-parse --short HEAD)"
+
+GO_CFLAGS=-X 'github.com/safedep/pmg/cmd/version.commit=$(GITCOMMIT)' -X 'github.com/safedep/pmg/cmd/version.version=$(VERSION)'
+GO_LDFLAGS=-ldflags "-w $(GO_CFLAGS)"
 
 .PHONY: all
 
 all: pmg
 
 pmg: create_bin
-	$(GO) build -o $(BIN) main.go
+	$(GO) build ${GO_LDFLAGS} -o $(BIN) main.go
 
 create_bin:
 	mkdir -p $(BIN_DIR)