Rlapi

This release focuses on migration to the new Rocket League API.

**Breaking changes:**
- Removed `rlapi.utils` module
- Removed `Playlist.tier_max` instance attribute
- use `Playlist.TIER_MAX` class attribute instead
- `platform.value` is now no longer the same as `str(platform)`
- The library is now using the new Rocket League API which requires a client ID and secret from Epic Games Developer Portal, instead of the old token.
As a result, following breaking changes have been made:
- `Client` now has 2 required keyword arguments `client_id` and `client_secret` instead of `token`.
- `Client.change_token()` has been removed in favor of `Client.update_client_credentials()`
- `Client.get_player()` for Epic Games platform now requires Epic Account ID, instead of Epic Display Name.
- This is a limitation of the new API.
- `Player.user_name` is now only present for PlayStation 4, Xbox One, and Nintendo Switch players.
This change corresponds to the platforms for which the player lookup requires the player's user name.
- This is a limitation of the new API.
- `Player.user_id` is now present for Steam *and* Epic Games players.
This change corresponds to the platforms for which the player lookup requires the player's user ID.
- This is a limitation of the new API.

**Features:**
- Added `Client.close()` method

**Enhancements:**
- Library users can now install `aiohttp` in <3.5.4, 4.0) version range
- Library users can now install `lxml` in <4.4.2, 5.0) version range

**Fixes:**
- Fixed casing of the friendly name of the PlayStation 4 platform

**Features:**
- added Epic Games and Nintendo Switch platform
- added Tournaments playlist
- added new ranks

**Enhancements:**
- lib users can now install `aiohttp` 3.7.x and `lxml` 4.6.x

**Fixes:**
- `Player.highest_tier` now only includes the playlists that count towards season rewards
- this also fixes the value of `SeasonRewards.can_advance` in relevant cases
- due to API providing outdated value, a temporary fix for `Playlist.tier_max` has been included in this release
- fixed Tracker Network provider module

**Docs:**
- fixed the issue causing the license headers from rlapi's code to show in the documentation

Enhancements:
- added representations (`__repr__`) to all data classes
- `Player` objects are now hashable and comparable

Docs:
- fixed usage examples

Miscellaneous:
- project relicensed to Apache License 2.0

This release takes an effort towards making the attribute names more consistent with the Rocket League API.

Breaking changes:
- `user_id` from the payload is now in `Player.user_id` and the attribute can be `None` if the payload doesn't contain
`user_id` (as is the case for non-Steam players).
- `Player.player_id` now instead contains the `player_id` as passed to `Client.get_player()`.

Enhancements:
- Allow lib users to install `aiohttp` 3.6.x and `lxml` 4.5.x.
- Change `typing_extensions` req to only specify minimum version.

Breaking changes:
- loop can no longer be explicitly passed to `rlapi.Client` in `loop` kwarg

Fixes:
- update `MANIFEST.in` to include `py.typed`

Enhancements:
- add `py.typed` to `rlapi.ext.tier_breakdown` for proper type hint support
- improve breakdown type hints