Removed rxjs compat

package.json

@@ -183,7 +183,6 @@
     "remarkable": "^1.7.1",
     "rst2html": "github:thoward/rst2html#990cb89",
     "rxjs": "^6.3.3",
-    "rxjs-compat": "^6.3.3",
     "slate": "^0.33.4",
     "slate-plain-serializer": "^0.5.10",
     "slate-prism": "^0.5.0",