Added git commit id and git commit description for version info

Dockerfile

@@ -12,10 +12,12 @@ RUN test -z "$(gofmt -l $(find . -type f -name '*.go' -not -path "./vendor/*"))"
 
 RUN go test $(go list ./...) -cover \
     && VERSION=$(git describe --all --exact-match `git rev-parse HEAD` | grep tags | sed 's/tags\///') \
-    && GIT_COMMIT=$(git rev-list -1 HEAD) \
+    && GIT_COMMIT_ID=$(git rev-list -1 HEAD) \
+    && GIT_COMMIT_DESC=$(git log -1) \
     && CGO_ENABLED=0 GOOS=${OS} GOARCH=${ARCH} go build --ldflags "-s -w \
     -X github.com/appsbyram/seafoodtruck-slack/version.Version=${VERSION} \
-    -X github.com/appsbyram/seafoodtruck-slack/version.GitCommitDescription=${GIT_COMMIT}" \
+    -X github.com/appsbyram/seafoodtruck-slack/version.GitCommitID=${GIT_COMMIT_ID} \
+    -X github.com/appsbyram/seafoodtruck-slack/version.GitCommitDescription=${GIT_COMMIT_DESC}" \
     -a -installsuffix cgo -o bot
 
 FROM alpine:latest

app.go

@@ -107,8 +107,9 @@ func homeHandler(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
 		json := fmt.Sprintf(`{
 			"Version": "%s",
+			"GitCommitID": "%s",
 			"GitCommitDescription": "%s"
-		}`, version.Version, version.GitCommitDescription)
+		}`, version.Version, version.GitCommitID, version.GitCommitDescription)
 
 		buffer = []byte(json)
 		w.Write(buffer)

version/version.go

@@ -1,5 +1,5 @@
 package version
 
 var (
-	Version, GitCommitDescription string
+	Version, GitCommitID, GitCommitDescription string
 )