build-unit-test-docker: Add 'isoduration' to support ISO 8601 duration

As per the proposed design for syncing data to the redundant BMC, time
intervals need to be specified in seconds, minutes, or hours. For more
details, refer to the design document:
https://gerrit.openbmc.org/c/openbmc/docs/+/71039/4/designs/
redundant_bmc_data_synchronization.md#157

The JSON doesn't have a in-built infrastructure to represent time
intervals in seconds,minutes etc. So the schema draft 2019-09 supports
format where time intervals can be represented in ISO 8601 duration
format.

Refer #built-in-formats :
https://json-schema.org/understanding-json-schema/reference/string

But for parsing and validating the same it requires an additional
python package called `isoduration`.

Refer #validating-formats :
https://python-jsonschema.readthedocs.io/en/latest/validate/

The change installs the python package `isoduration` to the docker to
enable the support of ISO 8601 duration formats in JSON and schema
files.

Change-Id: I5489aa21118fa8852ed22f40570c2b77c00951e3
Signed-off-by: Arya K Padman <aryakpadman@gmail.com>
1 file changed