Add "krb_host" as a config option

[IsaacDim]

Describe your changes

Added "krb_host" as an optional parameter for Hive connections that use Kerberos as their authentication type.

Internal Jira ticket number or external issue link

Issue from @Mac-lp3 #153

Testing procedure/screenshots(if appropriate):

Checklist before requesting a review

• I have performed a self-review of my code
• I have formatted my added/modified code to follow pep-8 standards
• I have checked suggestions from python linter to make sure code is of good quality.

[IsaacDim]

Hi, this PR was made with @Mac-lp3.

We're not quite sure how to go about testing this change though. Are the changes to conftests.py sufficient?

[Mac-lp3]

Hi @niteshy,

This PR is for that separate kerberos host issue we spoke about ~last week (#153).

I got someone to submit the PR for me 🙃