Bump shelljs to 0.8.4

Silences the following kinds of warnings:

    Warning: Accessing non-existent property 'cd' of module exports
    inside circular dependency

Author: mwiencek

package.json

@@ -58,7 +58,7 @@
     "react-table": "7.3.2",
     "redux": "3.6.0",
     "shell-quote": "1.7.2",
-    "shelljs": "0.8.3",
+    "shelljs": "0.8.4",
     "sliced": "1.0.1",
     "tablesorter": "2.31.3",
     "terser-webpack-plugin": "1.3.0",

yarn.lock

@@ -6276,10 +6276,10 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/shell-quote/-/shell-quote-1.7.2.tgz#67a7d02c76c9da24f99d20808fcaded0e0e04be2"
   integrity sha512-mRz/m/JVscCrkMyPqHc/bczi3OQHkLTqXHEFu0zDhK/qfv3UcOA4SVmRCLmos4bhjr9ekVQubj/R7waKapmiQg==
 
-[email protected].3:
-  version "0.8.3"
-  resolved "https://registry.yarnpkg.com/shelljs/-/shelljs-0.8.3.tgz#a7f3319520ebf09ee81275b2368adb286659b097"
-  integrity sha512-fc0BKlAWiLpwZljmOvAOTE/gXawtCoNrP5oaY7KIaQbbyHeQVg01pSEuEGvGh3HEdBU4baCD7wQBwADmM/7f7A==
+[email protected].4:
+  version "0.8.4"
+  resolved "https://registry.yarnpkg.com/shelljs/-/shelljs-0.8.4.tgz#de7684feeb767f8716b326078a8a00875890e3c2"
+  integrity sha512-7gk3UZ9kOfPLIAbslLzyWeGiEqx9e3rxwZM0KE6EL8GlGwjym9Mrlx5/p33bWTu9YG6vcS4MBxYZDHYr5lr8BQ==
   dependencies:
     glob "^7.0.0"
     interpret "^1.0.0"