NET-236: Create stream by path

[teogeb]

The id parameter of client.createStream can be a path (or full stream id, as previously). It will be prefixed with a lowercased Ethereum address derived from user's private key.

E.g.

client.createStream({
    id: '/foo/bar'
})
// -> creates 0xabcdeabcde123456789012345678901234567890/foo/bar

[linear]

NET-236 Support for entering streamId in streamr-client-javascript

• End user can give streamId with convenience and ease
• Either raw, untamed full streamId
• Or just the path -part, in which case the domain will be determined automatically by the Ethereum address of which the client is aware of. In this case, the Ethereum address should be lowercased by the library.

[timoxley]

feels weird to pass in an id and get back an object with a different id but I guess the client itself does the same thing.

I added a test to check it wasn't possible to create a stream with another user's address as the prefix, it passed though perhaps client could detect this before it hits the backend and give a nicer error, maybe:
ffbb273

[teogeb]

feels weird to pass in an id and get back an object with a different id but I guess the client itself does the same thing.

I added a test to check it wasn't possible to create a stream with another user's address as the prefix, it passed though perhaps client could detect this before it hits the backend and give a nicer error, maybe:
ffbb273

Agree. Alternatively we could use something like createStream({ id: createStreamId('/foo/bar') } but it wouldn't be very readable. Maybe this is a good compromise. Backend validation is fine, but maybe error messages could be better.