Finally I found the problem. My Info.plist file was missing CFBundleIdentifier. After I added it, application was able to register in Notification Center.

<key>CFBundleIdentifier</key> <string>org.notifytestosx.app</string>

This commit has required fix:
https://github.com/beemaster/osxnotifytest/commit/fa4154eebf9ffa51f9f9e5de5d12239c18d02370