* [ws client]: unsubscribe directly

When a subscription is dropped because of `max_notifs_per_subscription` is exceeded
the client didn't send an `unsubcribe request` until the subscription was dropped which this commit fixes.

This causes the server to still send messages to the subscription and the client would get lots of
error messages `InvalidRequestId`

* address grumbles

* fix: rephrase and not use request everywhere.

* [ws client]: register request ID for unsubscribe.

Fixes #220

* refactor manager usage

* restrict request ID to u8

* Update ws-client/src/tests.rs

* rename `max_notifs_per_subscription_capacity`

* Update tests/src/lib.rs

* fix nits

* address grumbles: vecdeq for free slots

* resolve todo

* [request manager]: add test for max limit.

* Update ws-client/src/client.rs

Co-authored-by: David <[email protected]>

* fix stack overflow

* grumbles: MaxMemory -> MaxSlots

* address grumbles: stray capacity on configs

* Update types/src/client.rs

Co-authored-by: David <[email protected]>

* grumbles: stray confusing docs

* grumbles: doc nits

* grumbles: remove nested if let

Co-authored-by: David <[email protected]>

* prep for client release.

* fix nits

* add changelogs

* Update http-client/src/lib.rs

Co-authored-by: David <[email protected]>

* address grumbles: one changelog

* 0.2.0-alpha

* revert rust2018 lint

Co-authored-by: David <[email protected]>

* fix examples

* [ws client]: transport use `max_payload_size`

* fix nits

* fix more nits

* Update ws-client/src/client.rs

* fix doc tests

* [ws client]: all transport config configurable

* Update ws-client/src/client.rs

Co-authored-by: David <[email protected]>

* Update ws-client/src/manager.rs

Co-authored-by: David <[email protected]>

* address grumbles

* grumbles: WsDnsError -> WsHandshakeError

* grumbles: remove needless clone

* fix lint: remove explicit lifetime

* fix nits: channel capacity + docs

* clippy nits

* clippy nits

* fix grumbles: channel capacity 256

As Maciej pointed out the capacity is the number of messages (not bytes) and each message is 96 bytes.
Thus, 256 * 96 = ~24kB which is reasonable default value.

* Update ws-client/src/client.rs

Co-authored-by: David <[email protected]>

* grumbles: docs

Co-authored-by: David <[email protected]>

* update http example

* ungeneric crate

* update dependencies

* [client]: add WebSocket client again.

* [deps]: remove needless dev dependencies

* nits: forgot to commit new files

* [ws client]: `send_text` instead of `send_binary`

This is temporary fix to work with the `server` which assumes that
`WebSocket` resonses are `text`

* chore: add a bunch of more logging

* [ws]: port tests but some are failing.

* chore: fmt

* [server API]: expose `fn local_addr` as public API.

* [tests]: make them less ugly by using `127.0.0.1:0`

* fix: a bunch of compiler warnings.

* [api]: uniform naming, `bind -> new` in transport.

* [websocket server]: reply when deserial fails

When the server receives an request with invalid JSON
`-32700, Parse error shall be returned`

* chore: fmt

* [tests]: fix remaining tests

* [websocket server]: support `binary` and `text`

* [ws server]: fix bug in subscription response.

`.await` was missing in ...