A `[cfg(test)]` function is not as helpful as a macro since it can't be called in the context of a doctest. Also adds doctest_wallet macro which can be used to create a wallet in a doctest.
A `[cfg(test)]` function is not as helpful as a macro since it can't be called in the context of a doctest. Also adds doctest_wallet macro which can be used to create a wallet in a doctest.