Agents: key of agent tags is always being parsed as lower case

[manrodrigues]

When an agent tag is created, even if the key is created using upper letters, the key is being parsed as lowercase.

You can see here that the config file contains mixed (upper and lower) letters:

But only the value is created exactly as the file. The key is always lowercase:

As the groups subscriptions are case sensitive and that is impossible to ediiting agent tags using orb UI, the users are blocked to subscribe the agent to any preexisting group whose have upper letters on the key.

[manrodrigues]

@lpegoraro told that the problem is from it: https://github.com/spf13/viper/issues/260