Release 0.20.4

# History

## 0.20.4

Install/update via the bootstrap script:

```shell
wget https://raw.githubusercontent.com/dokku/dokku/v0.20.4/bootstrap.sh
sudo DOKKU_TAG=v0.20.4 bash bootstrap.sh
```

### New Features

- #3936: @josegonzalez Enable limiting and reserving gpu resources

### Documentation

- #3937: @josegonzalez Add minor documentation for the kubernetes and nomad schedulers

### Other

- #3935: @dependabot-preview[bot] chore(deps): bump jinja2 from 2.11.1 to 2.11.2 in /tests/apps/python-flask
- #3934: @dependabot-preview[bot] chore(deps): bump github.com/golang/protobuf from 1.3.5 to 1.4.0 in /tests/apps/gogrpc
- #3933: @dependabot-preview[bot] chore(deps): bump jetty-servlet from 9.4.27.v20200227 to 9.4.28.v20200408 in /tests/apps/java

plugins/plugin/plugin.toml

@@ -1,4 +1,4 @@
 [plugin]
 description = "dokku core plugin plugin"
-version = "0.20.3"
+version = "0.20.4"
 [plugin.config]