Fixing the schema resolver related Unit tests

Problem:

Following Unit Tests were failing consistently in schema-core

testResolveSchema_RefResolutionUnderDefinitions()
testResolveSchema_withDefinitionForRef()

Issue:

The UTs are related to resolution of schemas with references. One of the references being "https://xx" type of references. These are resolved by making Http call to specified server and not mocked. The output of external call can change over time and that's potentially what happened here.

Fix:

Updated the payload of UTs to reflect correct payload

Long term fix:

Description and asks are mentioned in this issue: #68 (closed)