switching config_teagent.sh to an erb template for the config file

[drenalin23]

This is sort of question about how things are set up. Is there a compelling reason that this cookbook install a shell script which edits /etc/te-agent.cfg, instead of just editing /etc/te-agent.cfg directly as an erb template?
Asking as we get errors on exit from the Shellout on 14.04 and if this was an erb template the file can just be directly updated without the need for a shell script.

[pcabido]

@drenalin23 Our agent software manages the configuration file itself so depending on how this is being used there was the potential to overwrite the configuration file which isn't ideal so we opted by this approach at the time. This was done a while back so it was also being done this way in a few other places and we ended up re-using.

I think that we can improve this. We're looking into it.

[drenalin23]

#12 is an example of writing the config file directly with chef.