Improve error message in tr.b.Unit.fromJSON

Improve error message in tr.b.Unit.fromJSON

Review-Url: https://codereview.chromium.org/2996873002
Committed: https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+/598a1a1f3f2bda7739aa3b855403a6b9071c909b

[benjhayden, 2017-08-11 05:44:20]

benjhayden@chromium.org changed reviewers:
+ eakuefner@chromium.org

[benjhayden, 2017-08-11 05:44:21]

From https://chromium-review.googlesource.com/c/610949

[eakuefner, 2017-08-18 23:20:33]

lgtm

[benjhayden, 2017-08-19 01:49:43]

The CQ bit was checked by benjhayden@chromium.org

[commit-bot: I haz the power, 2017-08-19 01:49:54]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-08-19 02:16:46]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1503107383532540, "parent_rev":
"446ec6522de19e62b6967b257b28c78a1753eb92", "commit_rev":
"598a1a1f3f2bda7739aa3b855403a6b9071c909b"}

[commit-bot: I haz the power, 2017-08-19 02:16:49]

Description was changed from

==========
Improve error message in tr.b.Unit.fromJSON
==========

to

==========
Improve error message in tr.b.Unit.fromJSON

Review-Url: https://codereview.chromium.org/2996873002
Committed:
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...
==========

[commit-bot: I haz the power, 2017-08-19 02:16:50]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...