Integration tests for TS-based implementation of encryption/decryption/IPFS flow

[michaltakac]

Currently blocked by #5 and #44.

Encryption/decryption should be pretty easy to write integration tests for (as we're talking about client-side cryptography on files). For IPFS integration tests, we can leverage something like MockIPFS.

MockIPFS lets you build a fake IPFS node, or proxy traffic to a real IPFS node, and inspect & mock the interactions made by your IPFS API client