[TASK] Amount: Constants should be static fields on the class, not a separate export.
Merge pull request #158 from justmoon/amount_constants

Amount: Constants should be static fields on the class, not a separate export.
[DOC] update release notes
[TASK] bump version to 0.8.0-rc3
Clean up
* Make npm test runnable in Windows.
* Fix paths in README.md
* Ignore all build output files