Updated Procfile format and proctype checks

Adds an additionally support format for proctypes which is backwards compatible with foreman.

**Example**: (new mixed with old)

```yaml
redis:
  command: redis-server --port $PORT
  check:   redis-cli -p $PORT ping
  retry:   3
  delay:   1000
web: ./dist/build/webservice/webservice -p $PORT
```

**Defaults**:

* `check`: `Nothing`
*  `retry`: `0`
* `delay`: `1000`

The `check` command is used in conjunction with the supplied options to halt the startup procedure after `command` has been run until `check` succeeds.

This ensures service dependencies with long startup times (see: `JVM`) will be available and ready before subsequent `command`s are run.