**Apache Airflow version**:  1.10.10


**Kubernetes version (if you are using kubernetes)** (use `kubectl version`): v1.15.11

KubernetesPodOperator truncates logs when container produces more than 10 lines of logs before execution of `read_pod_logs` function. Is there any reason to make 10 as default value for `tail_lines` argument ?
```python
    def read_pod_logs(self, pod: V1Pod, tail_lines: int = 10):
        """Reads log from the POD"""
        try:
            return self._client.read_namespaced_pod_log(
                name=pod.metadata.name,
                namespace=pod.metadata.namespace,
                container='base',
                follow=True,
                tail_lines=tail_lines,
                _preload_content=False
            )
        except BaseHTTPError as e:
            raise AirflowException(
                'There was an error reading the kubernetes API: {}'.format(e)
            )
```
airflow/kubernetes/pod_launcher.py
"""Status of the PODs"""
    PENDING = 'pending'
    RUNNING = 'running'
    FAILED = 'failed'
    SUCCEEDED = 'succeeded'
class PodLauncher(LoggingMixin):
    """Launches PODS"""
    def __init__(self,
                 kube_client: client.CoreV1Api = None,
                 in_cluster: bool = True,
                 cluster_context: Optional[str] = None,
                 extract_xcom: bool = False):
        """
        Creates the launcher.
        :param kube_client: kubernetes client
        :param in_cluster: whether we are in cluster
        :param cluster_context: context of the cluster
        :param extract_xcom: whether we should extract xcom
        """
        super().__init__()
        self._client = kube_client or get_kube_client(in_cluster=in_cluster,
                                                      cluster_context=cluster_context)
        self._watch = watch.Watch()
        self.extract_xcom = extract_xcom
    def run_pod_async(self, pod: V1Pod, **kwargs):