fix pattern for img download

to handle SI:7 agent
more scala way to handle async image download
Merge pull request #334 from tyrcho/master

fix issue 332
Merge pull request #335 from tyrcho/fixes

New fixes from tyrcho
Merge pull request #337 from tyrcho/master

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Release notes for v0.17.2
Update Version To 1.7.2

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Maven release versions updated to v0.17.2 by mvn release:prepare
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Merge remote-tracking branch 'origin/master'
scala file
fix for non collectible returned by API