Use templates not lineinfile

[leifmadsen]

This resolves issue #20

[Ahmed]

I was like wtf, why he is not using a template?

[leifmadsen]

@Ahmed well, it makes sense when the configuration file could change / add more values etc, so the lineinfile option makes sense since it keeps things a little more intact / version agnostic.

I personally have just found writing the regex and and such to be a little more effort than it's worth, especially when the template is relatively short.

[geerlingguy]

I was like wtf, why he is not using a template?

I often use lineinfile if I need to change < 5 variables in a template, for a few reasons:

1. I can use the system packaged default template (which varies by OS and version somewhat, usually)
2. I don't have to maintain a monolithic template that is now used across all OSes and versions
3. There's a lot less Ansible configuration involved (see the diff here).

That said, I do switch to including and copying a template when the situation warrants it... and it may here. It looks like it at least works across all the main supported OSes with the current ES version.