useMutation incorrectly includes errorPolicy in its option types

[Jayphen]

The types for useMutation indicate that it does support errorPolicy.

useMutation is typed with OperationVariables as the second parameter: https://github.com/apollographql/react-apollo/blob/master/packages/hooks/src/useMutation.ts#L8

OperationVariables has an errorPolicy type https://github.com/apollographql/react-apollo/blob/master/packages/common/src/types/types.ts#L34

Thus, the typings for useMutation indicate that it supports errorPolicy, when in fact the setting will be silently ignored.

@apollo/react-hooks 3.0.1

[jamesreggio]

I've opened a PR here: apollographql/apollo-client#5863