**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
volume_mounts = [k8s.V1VolumeMount(
            mount_path='/etc/foo',
            name='test-volume',
            sub_path=None,
            read_only=True
        )]
        init_environments = [k8s.V1EnvVar(
            name='key1',
            value='value1'
        ), k8s.V1EnvVar(
            name='key2',
            value='value2'
        )]
        init_container = k8s.V1Container(
            name="init-container",
            image="ubuntu:16.04",
            env=init_environments,
            volume_mounts=volume_mounts,
            command=["bash", "-cx"],
            args=["echo 10"]
        )
        volume = k8s.V1Volume(
            name='test-volume',
            persistent_volume_claim=k8s.V1PersistentVolumeClaimVolumeSource(
                claim_name='test-volume'
            )
        )