Updated Node-sass, Grunt-sass & Jest-cli to clean up subdependencies.

[Dieterrr]

Summary

This PR can be summarized in the following changelog entry:

• N/A. Updated Node-sass, Grunt-sass & Jest-cli to clean up subdependencies.

Relevant technical choices:

• The original issue was to update Cryptiles to 4.1.2, but instead it has been removed as a dependency. Cryptiles was a dependency of hawk. Which was a dependency or request. Request was used by Node-sass, Grunt-sass & Jest-cli, and this resulted in 3 different versions of request in the yarn.lock file. I have updated all 3 to their latest versions which now all use the latest request(2.88) version. This has two advantages:
  -only one request version is used instead of several.
  -request does not use hawk (and therefore cryptiles) anymore since version 2.87 so instead of updating these dependencies we simply have removed them.

• Updates Merge to 1.2.1

• Updates Randomatic to 3.0.0

• After updating an error was thrown in the Travis, this was solved by adding an testurl to the jest configuration as noted here: JSDom 11.12 causes SecurityError: localStorage is not available for opaque origins jestjs/jest#6766

Test instructions

This PR can be tested by following these steps:

• Checkout this branch.
• Just to be sure, delete the node_modules and dist folder.
• Rebuild all the files by running yarn and grunt.
• All tests should pass, nothing should break. There should be no changes.

UI changes

• This PR changes the UI in the plugin. I have added the 'UI change' label to this PR.

Fixes #837
Fixes #838
Fixes #839

[andizer]

Acceptance done 👍