Require a pass in PHP 5.5
Add custom docs theme derived from Celery theme
PSR-2 formatting fixes
Unmarshal Decimal to float instead of string
Limit permitted values in String type via 'allowed' option
Move 'allowed' to noop group
Test successful 'allowed' case
DomainObject::lock no longer throws stale exceptions, provides closure
to opt-in instead.
Renaming Collection::order() to orderBy()
Fix chaining of orderBy, add andOrderBy method and add test
Fix orderBy(): now resets the ordering.

`orderBy()` replaces the existing ordering array.
`andOrderBy()` adds an extra sorting key.
Remove the deprecation message in order()

Please note that the function is still deprecated and usage is discouraged. Please use orderBy() instead.
Moved docs requirements file to root for readthedocs.org
Fallback to default docs theme
Fixed failing tests
Removed doc elements that were causing warnings
Removed missing doc references
Fix to make Collection::order chainable again
Updated change log