btn-launch incorrectly declared for launch instance NG

[Richard Jones]

The code declaring the launch instance NG buttons currently has the classes attribute as:

    classes = ("btn-launch")

this should be a sequence of strings, not a single string.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/208316
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=9d3823b3d83b7ac4206898ba72bc300529d690f3
Submitter: Jenkins
Branch: master

commit 9d3823b3d83b7ac4206898ba72bc300529d690f3
Author: Richard Jones <email address hidden>
Date: Mon Aug 3 15:47:54 2015 +1000

    JSCS Cleanup - style guide cleanup for Launch Instance wizard

    Following John Papa's style guide
    https://github.com/johnpapa/angular-styleguide,
    this patch refactors the Angular code for Launch Instance wizard.

    Note that the construction of the Launch Instance wizard precludes
    applying JP's "controller as" rule to the top level wizard controller
    itself; doing so breaks the *many* implicit parent accesses throughout
    the wizard sub controllers (implicit parent scope accesses are not
    possible using the "controller as" style). Fixing that is potentially
    a flow-on tech-debt fix that is outside of the scope of this
    patch - it'll be a bunch of work!

    I also noticed a trivial bugfix while addressing this. It could be
    broken out into a separate patch, but we have enough patches already ;)

    Change-Id: Ie6a1fdca1da60259adbb65c36a9829b001ae752b
    Partially-Implements: blueprint jscs-cleanup
    Closes-Bug: 1481135