feat: Can now set default value of a json property
bug: Change to satisfy dart analyzer
Added mock dev dependency

- unittest library dropped the `mock` dependency, so we have to add it
  back
test: Small test warnings
feat: Added RPC wrapper

So that automatic request retrys don't fail with a `request already
finalised` error.
chore: Satisfy analyzer

Although I think the error is invalid
feat: Upload tokens

Upload status is now resumable across sessions of the connection
test: Added upload tests
chore: Added .DS_Store to .gitignore