remove eshell/history file

There was nothing much in it; I guess because I don't usually use
eshell. Removing because its weird to have history in the repo.
.gitignore .emacs.d/eshell/history

So that it won't show up in the repo any more ever again.
Merge pull request #8 from ajschumacher/remove_history

remove eshell/history - resolves #7