Fix issue #19

Multiple where clauses on the same attribute with different values
should be differentiated in the bindings so that neo4php driver doesn’t
mess up the values.
Fix issue #18

Now we post-fix all the update bindings with an “_update” string so
that they don’t clash with bindings set by the where clause.
Support null and boolean values preservicing types

When creating and updating all values should be taken as is.
Return updated nodes count
add getQualifiedKeyName to mocked model
Fix #13 and #17

Pass the attributes of createWith through the prepareForCreation method
which takes care of all the required preparations.