[EnMasse] Changelog for releases

[Ulf Lilleengen]

Hi,

I've started to maintain a changelog[1] so that we can keep track of 
what ends up in different releases of EnMasse.

To make that job easier, I propose a simple guideline that doesn't cost 
much in terms of developer effort: whenever you work on a github issue 
and resolve it, set the milestone to the _next_ release version of 
EnMasse [2]

The next version is likely to be 0.(N+1).0 for some time, and then we 
can revisit this when we need to think about major releases or if this 
approach doesn't work.

wdyt?

[1] https://github.com/EnMasseProject/enmasse/blob/master/CHANGELOG.md
[2] https://github.com/EnMasseProject/subserv/issues/19

-- 
Ulf