[ML-5603] remove tests resources from release jar

[mengxr]

Currently the release jar contains test resources and scala library, which makes the release jar very large and error-prone. This PR removes test resources and scala from the release jar.

It reduces the release jar from 7MB to 230KB.

[jkbradley]

Comparing publishLocal JAR, this removes:

64a65,78
> docs/
> docs/_build/
> docs/_build/html/
> docs/_build/html/_static/
> docs/_build/html/_static/comment-bright.png
> docs/_build/html/_static/comment-close.png
> docs/_build/html/_static/comment.png
> docs/_build/html/_static/down-pressed.png
> docs/_build/html/_static/down.png
> docs/_build/html/_static/file.png
> docs/_build/html/_static/minus.png
> docs/_build/html/_static/plus.png
> docs/_build/html/_static/up-pressed.png
> docs/_build/html/_static/up.png
175a190,203
> tests/
> tests/resources/
> tests/resources/images/
> tests/resources/images/00074201.jpg
> tests/resources/images/00081101.jpg
> tests/resources/images/00084301.png
> tests/resources/images/00093801.jpg
> tests/resources/images/19207401.jpg
> tests/resources/images/1_channels/
> tests/resources/images/1_channels/00074201.png
> tests/resources/images/3_channels/
> tests/resources/images/3_channels/00074201.png
> tests/resources/images/4_channels/
> tests/resources/images/4_channels/00074201.png

Comparing the assembly JAR, this removes scala/, the above images, and:

> library.properties
> reflect.properties
> rootdoc.txt

LGTM