**Apache Airflow version**: 1.10.12

**Kubernetes version** : 1.17.9

**Environment**:

- **Cloud provider or hardware configuration**: Azure Kubernetes Service
- **OS** (e.g. from /etc/os-release): Linux
- **Install tools**: Helm chart (/chart in repo) 
- **Others**:

**What happened**:
Pod cannot run since `airflow-cleanup-pods` is not in $PATH
```
Error: failed to start container "airflow-cleanup-pods": Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "exec: \"airflow-cleanup-pods\": executable file not found in $PATH": unknown
```

**What you expected to happen**: 
Cleanup job pod runs

<!-- What do you think went wrong? -->

**How to reproduce it**:
* Deploy Helm Chart
* Manually trigger `airflow-cleanup ` CronJob 
* See it cannot run since `airflow-cleanup-pods` is not in $PATH
airflow/cli/cli_parser.py
)
ARG_PORT = Arg(
    ("-p", "--port"),
    default=conf.get('webserver', 'WEB_SERVER_PORT'),
    type=int,
    help="The port on which to run the server")
ARG_SSL_CERT = Arg(
    ("--ssl-cert",),
    default=conf.get('webserver', 'WEB_SERVER_SSL_CERT'),
    help="Path to the SSL certificate for the webserver")
ARG_SSL_KEY = Arg(
    ("--ssl-key",),
    default=conf.get('webserver', 'WEB_SERVER_SSL_KEY'),
    help="Path to the key to use with the SSL certificate")
ARG_WORKERS = Arg(
    ("-w", "--workers"),
    default=conf.get('webserver', 'WORKERS'),
    type=int,
    help="Number of workers to run the webserver on")
ARG_WORKERCLASS = Arg(
    ("-k", "--workerclass"),
    default=conf.get('webserver', 'WORKER_CLASS'),
    choices=['sync', 'eventlet', 'gevent', 'tornado'],
    help="The worker class to use for Gunicorn")
ARG_WORKER_TIMEOUT = Arg(
    ("-t", "--worker-timeout"),
    default=conf.get('webserver', 'WEB_SERVER_WORKER_TIMEOUT'),
    type=int,
    help="The timeout for waiting on webserver workers")
ARG_HOSTNAME = Arg(