Merge branch 'develop' into nj/ui-changes

.travis.yml

package.json

src/components/action-menu/action-menu.jsx

src/components/loader/loader.jsx

src/components/sprite-selector/sprite-selector.jsx

src/components/stage-selector/stage-selector.jsx

src/containers/costume-tab.jsx

src/containers/monitor.jsx

src/containers/sb3-downloader.jsx

src/containers/sound-tab.jsx

src/containers/target-pane.jsx

src/lib/blocks.js

src/lib/default-project/index.js

src/lib/download-blob.js

src/lib/download-url.js

src/lib/file-uploader.js

test/fixtures/movie.wav

test/fixtures/sneaker.wav

test/integration/backdrops.test.js

test/integration/costumes.test.js