Feature/healthcheck improvements (#30)

* health check tests mysql and redis connectivity

* health check tests mysql and redis connectivity

* minor

liveness.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+TCP_SERVER_PORT="${DRACHTIO_PORT:-4000}"
+nc -v -z localhost $TCP_SERVER_PORT
+
+# if last command exited with non zero
+if [ $? != 0 ]
+then
+    exit 1
+fi
+
+HTTP_SERVER_PORT="${HTTP_PORT:-3000}"
+
+printf 'GET /system-health HTTP/1.1\r\nHost: localhost\r\n\r\n' | nc -v localhost 3000 | grep calls
+
+# grep will automatically exit with 1 if string is not matched, however, will leave that call there in case 
+# we pivot to pipe to dev/null
+
+if [ $? != 0 ]
+then
+    exit 1
+fi
+
+exit 0