Replace Github actions secrets with variables for non-sensitive data

[fjuniorr]

The following variables are defined as secrets in Github Actions making it inconvenient to troubleshoot CI issues that could be related to their values:

• CKANR_DEFAULT_URL
• CKANR_TEST_BEHAVIOUR
• CKANR_TEST_DID
• CKANR_TEST_GID
• CKANR_TEST_OID
• CKANR_TEST_RID
• CKANR_TEST_URL

[florianm]

I'm just bumping into this in #211 - would it make sense to set all non-sensitive test variables as defaults in ckanr_settings?

This way, any keen contributor could still override them to configure local tests, but the defaults could be made to work with the GH actions run. Bonus points for a contributing guide with steps to spin up a local CKAN via docker-compose.

ckanr_settings <- function() {
  ops <- list(url = Sys.getenv("CKANR_DEFAULT_URL", ""),
              key = Sys.getenv("CKANR_DEFAULT_KEY", ""),
              test_url = Sys.getenv("CKANR_TEST_URL", "http://localhost:5000/"),
              test_key = Sys.getenv("CKANR_TEST_KEY", ""),
              test_did = Sys.getenv("CKANR_TEST_DID", "EXAMPLE_VALUE"),
              test_rid = Sys.getenv("CKANR_TEST_RID", "EXAMPLE_VALUE"),
              test_gid = Sys.getenv("CKANR_TEST_GID", "EXAMPLE_VALUE"),
              test_oid = Sys.getenv("CKANR_TEST_OID", "EXAMPLE_VALUE"),
              test_behaviour = Sys.getenv("CKANR_TEST_BEHAVIOUR", "FAIL"),
              proxy = get("ckanr_proxy", ckanr_settings_env)
  )
  structure(ops, class = "ckanr_settings")
}