Make collectstatic run to completion

lms/envs/common.py

lms/static/css/vendor/images/treeview-default-line.gif

lms/static/css/vendor/images/treeview-default.gif

lms/static/sass/application.css

lms/static/sass/marketing-ie.css

lms/static/sass/marketing.css

lms/static/sass/sass_old/courseware/_sequence-nav.scss

lms/static/sass_old/.gitignore

lms/static/sass_old/README.md

lms/static/sass_old/_gradebook.scss

lms/static/sass_old/_help.scss

lms/static/sass_old/_info.scss

lms/static/sass_old/_profile.scss

lms/static/sass_old/_textbook.scss

lms/static/sass_old/application.scss

lms/static/sass_old/base/_base.scss

lms/static/sass_old/base/_extends.scss

lms/static/sass_old/base/_font-face.scss

lms/static/sass_old/base/_functions.scss

lms/static/sass_old/base/_reset.scss