Fix
* fix: Make .sub-nav--teacher, .sub-nav--student visible on small screens (1315)
* fix: make .sub-nav--teacher, .sub-nav--student visible on small screens
* Merge branch &39;master&39; into 927-small-screen-hides-level-editor-and-scoreboard-buttons
* Merge branch &39;master&39; of github.com:ocadotechnology/codeforlife-portal into 927-small-screen-hides-level-editor-and-scoreboard-buttons
* fix: Reduce margin between buttons to avoid line split on narrowest size
* fix: Adjust margin between buttons in subnav for teacher
* Merge branch &39;927-small-screen-hides-level-editor-and-scoreboard-buttons&39; of github.com:sebp999/codeforlife-portal into 927-small-screen-hides-level-editor-and-scoreboard-buttons
* chore: catch up with master
* chore: generate Pipfile.lock ([`a2c64b6`](https://github.com/ocadotechnology/codeforlife-portal/commit/a2c64b6d81c24c6bd3ff6c8784ab38f6db66caa0))