Fix classrooms in IE11
Fix classrooms in IE11

Convert PieComponent from ES6 to ES5

This is separate from commit 79b23d81db27e246be60f11654ee768cd3cb15d9
on master because there are changes on this branch to the PieComponent.
This commit will override that commit.

javatlacati/codecombat,javatlacati/codecombat,jeremiahyan/codecombat,codecombat/codecombat,javatlacati/codecombat,jeremiahyan/codecombat,codecombat/codecombat,jeremiahyan/codecombat,codecombat/codecombat,codecombat/codecombat,codecombat/codecombat,jeremiahyan/codecombat,javatlacati/codecombat,javatlacati/codecombat