Added template support for cisco_fxos show system firmware

[manofcolombia]

There are currently no other cisco_fxos templates and I ran into a need to check both the running firmware against the startup firmware version in order to confirm that an upgrade was successful (you would think the api would let you confirm this but alas...no) so I made this template to scrape that info from cli.

[mjbear]

@manofcolombia
I figured out what needed to be fixed for the test cases and submitted a PR to your fork. This way you can merge my PR into your branch to have this fixed up! manofcolombia#1

[manofcolombia]

@mjbear Thank you. When I ran the tests locally it appeared to me that the failure was irrelevant to my commit, but now I understand what was going on and that I missed adding the new OS into the testing phase altogether. I will note this for myself.

[mjbear]

@mjbear Thank you. When I ran the tests locally it appeared to me that the failure was irrelevant to my commit, but now I understand what was going on and that I missed adding the new OS into the testing phase altogether. I will note this for myself.

No worries @manofcolombia. Glad to assist.

I don't believe in all my commits that I've added templates to an OS that didn't already exist, so this was a new item for me. haha 😆

Edit: grammar/thought