The writeErrorLogFile function outbuts errors as a sequence of concatenated stringified JSON objects instead of an array. That makes the resulting .json log file invalid.

E.g. the exampleErrorLog from tests results in the following log file:

{"ts":"2018-01-01T00:01:43.000Z","level":"warning","warning":"warning text"}{"ts":"2018-02-02T01:02:22.000Z","level":"error","error":{}}

Instead it would be nice for the output to be actual JSON:

[{"ts":"2018-01-01T00:01:43.000Z","level":"warning","warning":"warning text"},{"ts":"2018-02-02T01:02:22.000Z","level":"error","error":{}}]

The issue is mildly annoying, because the contentful-cli error logs require pre-processing to be parsed