Merge branch 'develop' into a11y-improvements

# Conflicts:
#	demo/dist/demo.css
#	dist/plyr.css
#	dist/plyr.js.map
#	dist/plyr.min.js
#	dist/plyr.min.js.map
#	dist/plyr.polyfilled.js.map
#	dist/plyr.polyfilled.min.js
#	dist/plyr.polyfilled.min.js.map
#	package.json
#	src/js/plyr.js

src/sass/components/controls.scss

@@ -109,3 +109,11 @@
 .plyr--fullscreen-enabled [data-plyr='fullscreen'] {
     display: inline-block;
 }
+
+.plyr__controls:empty {
+    display: none;
+    
+    ~ .plyr__captions {
+        transform: translateY(0);
+    }
+}