Required parameters are not checked

[fschoell]

Requesting data from an endpoint that has required parameters, but not sending those parameters results in an empty data response (instead of an error).

For example /transfers requires contract and symcode as of the Swagger docs.
If you access http://eos.antelope-token-api.pinax.mar-prod1.pinax.io/transfers directly it doesn't result in an error message, but just in an empty response which is misleading for users.

Expected Behavior

Return a proper error describing which parameters are missing.

Current Behavior

Returns an empty data array.