Add .git directory to npmignore
Add .git directory to npmignore

I am not sure why this suddenly became an issue, but it appears that `.git` is being published to npm now, at least for ember-shepherd. It might be related to me recently updating node/npm and perhaps it used to be ignored by default, but we probably do not want to publish the `.git` directory, so this should ignore it. Related issue is here https://github.com/shipshapecode/ember-shepherd/issues/319
thoov/ember-cli,jgwhite/ember-cli,thoov/ember-cli,buschtoens/ember-cli,HeroicEric/ember-cli,asakusuma/ember-cli,elwayman02/ember-cli,asakusuma/ember-cli,balinterdi/ember-cli,balinterdi/ember-cli,jgwhite/ember-cli,HeroicEric/ember-cli,jrjohnson/ember-cli,kategengler/ember-cli,ember-cli/ember-cli,raycohen/ember-cli,jgwhite/ember-cli,raycohen/ember-cli,kategengler/ember-cli,buschtoens/ember-cli,ember-cli/ember-cli,HeroicEric/ember-cli,jrjohnson/ember-cli,thoov/ember-cli,jgwhite/ember-cli,HeroicEric/ember-cli,thoov/ember-cli,elwayman02/ember-cli,ember-cli/ember-cli