SumOf does not work on Iterable<Integer>

See #950, release log:

• 32c96d9: (#950) SumOf does not work on ...
• c49e9a2 by @rultor: Merge branch '__rultor'
• 5c2b766 by @rultor: Merge branch '__rultor'
• a2a51f4 by @llorllale: Javadoc fix for #937
• 504649d by @rultor: Merge branch '__rultor'
• 4dfdea1 by @victornoel: Use OO matchers instead of sta...
• 63ee642 by @victornoel: Avoid usage of null value in T...
• 494523f: #897, previous puzzle removed,...
• 050dd73 by @a6cexz: Corrected typo in the HexBytes...
• fb22f3c: #897, unit tests have been adj...
• 4348d7e: #897, all classes implementing...
• 84f7c9d by @rultor: Merge branch '__rultor'
• d5a130c by @llorllale: Version up 0.37-SNAPSHOT

Released by Rultor 1.68, see build log