Remove auto_impl

[sorpaas]

It's not no_std compatible. We still need to work on the no_std CI to make sure this does not happen again. rel #62 (comment)

[gakonst]

Can't we do cfg_attr(feature = "no_std", auto_impl(...)) as suggested here?

[sorpaas]

I'd prefer if we fix auto_impl since this should clearly be no_std compatible (all the types exist in no_std). Let me know if this is something you need urgently, otherwise I'd prefer to fix our CI first to make sure it does not happen again.

[sorpaas]

Also if this is not too complicated -- maybe consider manually implementing them!

[gakonst]

No worries - I am OK with just using a patched version of this repo for now. I will investigate if fixing making auto_impl no_std compatible is something I'll have the capacity to do!