Revert ".aliases: Alias `sha1sum` if needed"
Revert ".aliases: Alias `sha1sum` if needed"

The sha1sum alias was preventing nvm from installing node. Hat tip to
creationix/nvm#659 for making this a quick and easy fix.

This reverts commit af441ca (mathiasbynens/dotfiles#141).

cappadona/dotfiles,cappadona/dotfiles