Implement retrieval "Farm" APIs

[hoangpn]

Adding 2 APIs for retrieving Farm's data:

1. GET /rest/farm
   Returns a JSON array of all farms in Promgen.
   Available request params:

• source: string. The returned array of farms will be of this source type. Exact match.
• name: string. The returned array of farms will have the name which contains the parameter's value. Contains

Sample response:

[
    {
        "id": 1,
        "url": "http://127.0.0.1:8000/farm/1",
        "name": "farm-test",
        "source": "promgen"
    },
    ...
]

2. GET /rest/farm/:id
   Returns the farm matching the ID as a JSON object, including the list of hosts.

Sample response:

{
    "id": 1,
    "url": "http://127.0.0.1:8000/farm/1",
    "name": "farm-test",
    "source": "promgen",
    "hosts": [
        {
            "url": "http://127.0.0.1:8000/host/host-test.com",
            "name": "host-test.com"
        },
        ...
    ]
}

[CLAassistant]

All committers have signed the CLA.

[vincent-olivert-riera]

I have reviewed and tested your code.

I have left some comments for requested changes. Please check them.
If you have any question about them, please let me know.

Also, please add a commit message explaining the context for this commit. For instance, why are we doing all of this? Why do we need this new API end point?

Thank you very much!!!

[hoangpn]

@vincent-olivert-riera
Thank you for your comments. I have updated the source code according to your suggestion!

[vincent-olivert-riera]

Thank you for addressing all the comments. This looks good to merge, but there are a couple of missing new-line characters in the two JSON files that we have added. Please fix them.

Another thing I wanted to tell you. Since you have force-pushed all your changes, I had to review all your code again.
Instead, it is better to use the --fixup option. For instance, if you are making changes to the code that was previously added by commit 3e543e5, after doing git add to add the new changes, use git commit --fixup=3e543e5 to create a new commit, and then push it. That way you can tell me "I have addressed this comment on commit XXXXXX", and I can review only that.

After the review is complete and the code is considered good, you can easily squash all those extra "fixup" commits automatically by doing: git rebase -i master --autosquash, and do a final force-push.

Please, try to do it that way for the requested changes in the JSON files. If you need any help, please ask me.

Thank you very much!

[vincent-olivert-riera]

Looks good to me!

Please, squash all the fixup commits for final review and approval.

Thanks!

[hoangpn]

Thank you so much. I squashed and force pushed for final review. 🙇

[vincent-olivert-riera]

Looks good to me.