"Slave 10.1.2.125 is unreachable" & "Abnormal executor termination: unknown container" is not reported by complainer

Those two errors are not reported by complainer:

```
On 15/05/17 07:11, "chronos@mesos0.company.com" wrote:

'2017-05-15T05:11:50.632Z'. Retries attempted: 0.
Task id: ct:1494819000000:0:groundhog-HoteDescriptionDispatcher:
The scheduler provided this message:

Slave 10.1.2.3 is unreachable
```

and

```
On 14/05/17 06:56, "chronos@mesos0.company.com" wrote:

'2017-05-14T04:56:57.846Z'. Retries attempted: 0.
Task id: ct:1494732600000:0:groundhog-HoteDescriptionDispatcher:
The scheduler provided this message:

Abnormal executor termination: unknown container
```

Those two issues were send via email by Chronos / Mesos

Start by locating the Go code that parses Mesos or Chronos task-failure messages and sends notifications; no file or test is named in the issue. Use the two quoted errors as inputs and verify that both are reported by complainer without breaking existing failure handling.

Written by the indexing model from the issue text.