**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)
            )
```
kubernetes_tests/test_kubernetes_pod_operator.py
dag = DAG(dag_id="dag")
    tzinfo = pendulum.timezone("Europe/Amsterdam")
    execution_date = timezone.datetime(2016, 1, 1, 1, 0, 0, tzinfo=tzinfo)
    task_instance = TaskInstance(task=task,
                                 execution_date=execution_date)
    return {
        "dag": dag,
        "ts": execution_date.isoformat(),
        "task": task,
        "ti": task_instance,
    }
class TestKubernetesPodOperatorSystem(unittest.TestCase):
    def get_current_task_name(self):
        
        return "_" + unittest.TestCase.id(self).replace(".", "_")[::-1]
    def setUp(self):
        self.maxDiff = None  
        self.api_client = ApiClient()
        self.expected_pod = {
            'apiVersion': 'v1',
            'kind': 'Pod',
            'metadata': {
                'namespace': 'default',
                'name': ANY,
                'annotations': {},
                'labels': {
                    'foo': 'bar', 'kubernetes_pod_operator': 'True',
                    'airflow_version': airflow_version.replace('+', '-'),