Handle FileStorage directory internally

[pedrouid]

The Problem

Currently payment-bot works with store module using FileStorage because of the entry.sh script which handles the directory creation prior to execution, this won't however be the same behavior for someone else using the module

The Solution

Remove directory handling logic in entry.sh script and handle it synchronously on the FileStorage constructor

Checklist:

• I am making this PR against staging, not master
• My code follows the code style of this project.
• I have described any backwards-incompatibility implications above.
• I have highlighted which parts of the code should be reviewed most carefully.
• If my change requires a change to the documentation, I have updated it accordingly.

[todo-tracker]

Hey, pedrouid

We noticed you made changes to a file with a TODO on it.
These are set to make sure potential Technical Debt doesn't get forgotten.
While you're here take a shot at turning a listed TODO into a TODONE!

Id	Name	File	Priority
71	merge:	modules/client/src/node.ts	Normal
83	should add once to top level client	modules/test-runner/src/util/helpers/fundChannel.ts	Normal
85	events for withdrawal commitments! issue 698	modules/test-runner/src/withdraw/withdraw.test.ts	Normal