Hallie Dunham

### Please check if the PR fulfills these requirements - [x] CHANGELOG.md is updated - [x] Tests for the changes have been added (for bug fixes / features) - [x]...

see discussion here: https://github.com/NREL/REopt_API/pull/343#discussion_r944825301_

(this is for job/ app aka v3) An ElectricUtility instance doesn't get saved in the database if it isn't in the user inputs. It should always be created/saved in non-off-grid...

add API job/ tests with posts that include all optional model keys

1

All models that don't get created unless the user includes them (e.g. CHP) need to be included in a test post. We need to do this to make sure all...

add capability to job/ app (API v3 using REopt.jl backend) to handle CHP

4

### Please check if the PR fulfills these requirements - [x] CHANGELOG.md is updated - [x] Tests for the changes have been added (for bug fixes / features) - [x]...

* **I'm submitting a ...** - [x] bug report - [ ] feature request - [ ] support request => Please do not submit support request here, see note at...