created scaffold of softwares.
added softwares definition.
added routes for softwares.
defined the associations of user and softwares.
added uniqueness and confirmation validations to :email.
and wrote specs.
added default before_actions to application_controller.
and wrote specs.
applied the authenticated filter to each actions.
and fixed the spec.
implements the user_controllers.
implements the view of sign up.
changed the path of 'sessions#new' to 'welcome'.