I downloaded OKTA default test suite from, http://developer.okta.com/standards/SCIM/SCIMFiles/Okta-SCIM-20-SPEC-Test.json. I uploaded this to Runscope and tried to execute tests (I am referring to line number 782 in this json file.)
I noticed that “Required Test: Create Okta user with realisitic values” test case in OKTA SCIM default test which is a POST request to Create user resource (“Required Test: Create Okta user with realisitic values” POST {{SCIMBaseURL}}/Users) does not have Content-Type (In Line 782 in attached json file). Is this intended or it's a bug? When the “Content-Type” is not presented in the request, our SCIM Api returns Http Status Code 415.
I suggest setting up at template SCIM app in an Okta developer edition org and see what it sends as a Content-Type header, then modify your Runscope tests to use that header.
I also recommend that you open a ticket with developers@okta.com so you can get more personalized help on your integration.