Fix doubling up on URL segments for Account currency methods

[ConnorMac]

When trying to PATCH/PUT a currency resource attached to a account resource it appends an extra currency code segment to the url, see below:

rehive.admin.accounts.obj("ZQTVXSC6H6").currencies.obj('ZAR').patch(
                active=True
            )

Yields a URL: /3/admin/accounts/ZQTVXSC6H6/currencies/ZAR/ZAR/

[OdinsPlasmaRifle]

@ConnorMac Can you take a look at these 2 PRS, It seems like we somehow ended up with 2 solutions to this problem however I am not sure the proposed solution from Almabud actually resolved it:

• Object/obj resource creation duplication issue #82
• [fix_currency_url,63] Fixed doubling resource_id in the url build section. #99