**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
("-H", "--hostname"),
    default=conf.get('webserver', 'WEB_SERVER_HOST'),
    help="Set the hostname on which to run the web server")
ARG_DEBUG = Arg(
    ("-d", "--debug"),
    help="Use the server that ships with Flask in debug mode",
    action="store_true")
ARG_ACCESS_LOGFILE = Arg(
    ("-A", "--access-logfile"),
    default=conf.get('webserver', 'ACCESS_LOGFILE'),
    help="The logfile to store the webserver access log. Use '-' to print to "
         "stderr")
ARG_ERROR_LOGFILE = Arg(
    ("-E", "--error-logfile"),
    default=conf.get('webserver', 'ERROR_LOGFILE'),
    help="The logfile to store the webserver error log. Use '-' to print to "
         "stderr")
ARG_NUM_RUNS = Arg(
    ("-n", "--num-runs"),
    default=conf.getint('scheduler', 'num_runs'),
    type=int,
    help="Set the number of runs to execute before exiting")
ARG_DO_PICKLE = Arg(
    ("-p", "--do-pickle"),
    default=False,
    help=(
        "Attempt to pickle the DAG object to send over "
        "to the workers, instead of letting workers run their version "
        "of the code"),
    action="store_true")