* adding NonResourceURLs support to access_store
* added tests to AccessSet NonResourceURLs handling
* change on test script suggested by @tomleb + go mod tidy
* added nonresource to ext api authorization
* added NonResourceURLs implementation in Authorizes + test
* removed non-resource-url tests from the main test
* added new tests for non-resource-urls
* removed unused test data
* changed nonResourceKey to point to struct{}
* addressed comments from @tomleb
* addressed more comments
* fixing typo
* check for empty accessSet
This implements the Imperative API that is served at /ext with Steve. The imperative API is compatible with Kubernetes' API server and will be used as an extension API server.
