#### What type of PR is this?
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Add one of the following kinds:
/kind bug
/kind cleanup
/kind documentation
/kind feature
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#### What this PR does / why we need it:
When supplying a label in the compose file, it should stay in the output
too.
#### Which issue(s) this PR fixes:
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*Automatically closes linked issue when PR is merged.
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
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Fixes https://github.com/kubernetes/kompose/issues/1885
#### Special notes for your reviewer:
Signed-off-by: Charlie Drage <charlie@charliedrage.com>
