Feature: adding optional sslmode parameter to postgres connection

[0xdholleran]

resolves #2152

Description

added functionality to add 'sslmode' parameter to a postgres profile connection

Checklist

• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have updated the CHANGELOG.md and added information about my change to the "dbt next" section.

[cla-bot]

Thanks for your pull request, and welcome to our community! We require contributors to sign our Contributor License Agreement and we don't seem to have your signature on file. Check out this article for more information on why we have a CLA.

In order for us to review and merge your code, please submit the Individual Contributor License Agreement form attached above above. If you have questions about the CLA, or if you believe you've received this message in error, don't hesitate to ping @drewbanin.

CLA has not been signed by users: @dholleran-lendico

[0xdholleran]

hey @drewbanin , I'm not sure why the CLA check is failing, as I signed it, any ideas?

[beckjake]

@cla-bot check

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[beckjake]

Hey @dholleran-lendico, thanks for your contribution! The CLA is a bit of a manual process on our end :)

Could you please resolve the merge conflict and while you're at it, include a link to this PR in the changelog?

[beckjake]

Looks great, just some tiny changes. Thanks for the nice test!

[drewbanin]

This functionally LGTM if @beckjake is happy with the code!

Nice work on this one @dholleran-lendico - thanks for your contribution to dbt!

[beckjake]

Looks great, I'll merge this now!