fix(autocomplete): Renamed autocomplete directive

Renamed autocomplete directive as auto-complete so it doesn't conflict
with <input> tags's autocomplete attribute. In addition, the 'restrict'
property of both tags-input and auto-complete directives was changed
from 'A,E' to 'E' since they are supposed to be used as elements, not
attributes.

Closes #20.
chore(release): Bumped version to 0.1.5 [skip ci]