Enhance info endpoint to include gateway version

Extend the health endpoint and add gateway version information

Resolves: #733
Signed-off-by: Edward Wilde <ewilde@gmail.com>

gateway/version/version.go

@@ -0,0 +1,20 @@
+package version
+
+var (
+	//Version release version of the provider
+	Version string
+	//GitCommit SHA of the last git commit
+	GitCommitSHA string
+	//GitCommit message of the last commit
+	GitCommitMessage string
+	//DevVersion string for the development version
+	DevVersion = "dev"
+)
+
+//BuildVersion returns current version of the provider
+func BuildVersion() string {
+	if len(Version) == 0 {
+		return DevVersion
+	}
+	return Version
+}