Added test for the new articles form

A test has been added to check for the displaying of a form for creating
a new article.
Added the form to the html template

The file new.html.erb now has a form which sets the framework for a
functional way to create new articles. Form is not completely functional
at this stage.
Suppressed warnings

Removed the --warnings option to supress irrelevant warnings.
Re-added the sass gem

Gem sass, which had previously been removed, has been re-added, as the
warnings are no longer an issue with the removal of the --warnings flag
from the .rspec file. This gem was also necessary for the rendering of
the form.