undeclared dependency on zend-servicemanager about zend-hydrator

[Ocramius]

Related: #29

@achevo01 including the dependency is feasible, but was avoided upfront due to too many library inter-dependencies. I'd suggest polyfilling instead of adding another dependency.

[froschdesign]

zend-servicemanager is not strictly required for this component and therefore it is included in the suggest section of the Composer file:

zend-hydrator/composer.json

Lines 28 to 33 in c16f3d4

	"suggest": {
	"zendframework/zend-eventmanager": "^2.6.2 || ^3.0, to support aggregate hydrator usage",
	"zendframework/zend-serializer": "^2.6.1, to use the SerializableStrategy",
	"zendframework/zend-servicemanager": "^2.7.5 || ^3.0.3, to support hydrator plugin manager usage",
	"zendframework/zend-filter": "^2.6, to support naming strategy hydrator usage"
	},

So it would be an improvement if the dependency can be removed.

[Ocramius]

Handled in #87