Switch from jasmine to jest (#747)

Summary:
The reasons for switching to jest:
- easy snapshot testing so that we can easily verify the structure of the parse tree and MathML tree
- easy compilation of ES6 features for tests as we continue to expand our use of ES6

Test Plan:
- npm test

lint_blacklist.txt

@@ -4,6 +4,3 @@
 build/**
 node_modules/**
 dist/**
-
-# Third party code
-test/jasmine/**