Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.
Ref discussion: https://github.com/tendermint/tendermint/pull/1966Closes#1956
* tools: Remove redundant grep -v vendors/
This was used in conjunction with `go list <path>`, however `go list`
already ignores the vendor directory. This made this `grep -v` redundant.
* Missed an apostrophe