* `test/e2e` -> `test/e2e-selenium`

* add Cypress

* ESLint fixes

* MOAR cypress

* `integration` -> `tests`

* wire Cypress up to a hot e2e server

* linter fixes

* don't run in CI

* add baseline tests

* coerce empty strings to null when updating parameter values

* add ParameterIncludeEmpty

* add redux management for empty parameter value inclusion state

* use name+in keying for state management instead of hash keying

* update new redux method usages to name+in keying

* coerce empty Immutable iterables in onChangeWrapper

* OAS3 tests & support

* add included empty parameters to requests before dispatching to Swagger Client

* make empty inclusion interface prettier

* add tests for #4587

* linter fixes

* check for truthy value before reaching into property