Revert "Add optional merchant_token to get_invoice"#2

flavioescobar wants to merge 1 commit intojoinrepublic:settlement-apijoinrepublic/ruby-client:settlement-apifrom

flavioescobar:revert-1-add-optional-merchant-tokenflavioescobar/ruby-client:revert-1-add-optional-merchant-tokenCopy head branch name to clipboard