Implemented version check

Updated readme

src/go/lib/versioncheck/version_check_test.go

@@ -0,0 +1,58 @@
+package versioncheck
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestCheckUpdates(t *testing.T) {
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, _ := ioutil.ReadAll(r.Body)
+		m := strings.Split(string(body), ";")
+
+		advices := []Advice{
+			Advice{
+				Hash:     m[0],
+				ToolName: m[1],
+				Advice:   "There is a new version",
+			},
+		}
+
+		buf, _ := json.Marshal(advices)
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, string(buf))
+	}))
+	defer ts.Close()
+
+	msg, err := CheckUpdates(ts.URL, "pt-test", "2.2.18")
+	if err != nil {
+		t.Errorf("error while checking %s", err)
+	}
+	if msg == "" {
+		t.Error("got empty response")
+	}
+
+}
+
+func TestEmptyResponse(t *testing.T) {
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprint(w, "")
+	}))
+	defer ts.Close()
+
+	msg, err := CheckUpdates(ts.URL, "pt-test", "2.2.18")
+	if err == nil {
+		t.Error("response should return error due to empty body")
+	}
+	if msg != "" {
+		t.Error("response should return error due to empty body")
+	}
+
+}