Use swagger.yaml to define advanced search API endpoints

[max-zilla]

After discussions with AZ website team, we want to move onto next phase of search API (found at https://search-api.workbench.terraref.org/seasons):

• use swagger.yaml to define parameters and return values for each endpoint
• implement a hard-coded sample JSON document for each in short term

As discussed, idea to start:

• get list of seasons - return each name & date range
• given a season, return a list of valid plot names

this could potentially be handled by a standard 'filter' endpoint that handles interactions between season, plot, (eventually) experiment and germplasm - you pick one of those, you get back a subset of the others that apply, and so on. but we start simple.

[max-zilla]

treatment, experiment, cultivars name and cultivars ecotype

[tcnichol]

I created a branch for this and a pull request. It is :

https://github.com/terraref/search-api/pull/3

I'm going to label it Work In Progress as it likely needs some changes.

[max-zilla]

deployed on dev: https://search-api-dev.workbench.terraref.org/search-api/v1/ui/