Adding optional type for attributes
Adding info to the readme on how to specify the type, adding an additional
test to cover a computed property without a type
Added description of default_serializer_options 

In example it's used to set up root: false for controller
Add support for specifying the serializer for an association as a String.

This enables the deferral of the resolution of the serializer class to prevent NameError exceptions due to reference cycles between serializer classes.
Update README.md

Spelling and murkup mistakes fixed.
Fix global ``` self.root = false ```

Using the on_load hook does not change the defined root on
Serializer#inherited.

Related to #179
Add failing test to show behavior of custom serializer with nils.
Create DefaultSerializer so that as_json uses same interface.

This is to ensure that PORO's as_json is called if no serializer
is specified.

Original behaviour was that serializable_hash was being called,
overriding the as_json method.
Move DefaultSerializer from array_serializer.rb to serializer.rb
Remove pry-nav from gemspec.
Restore order of fields in hash to original order.
test cases by fblee

Merge remote-tracking branch 'fblee/master'
serialization test: respect root settings when root object is nil
Don't fail if object is nil, render null
changes to be able to specify multiple attributes with keys
Update README.md file to better describe scope.

This commit also corrects the code about deactivating globally the root name of arrays.
Merge pull request #218 from phcoliveira/patch-1

Update README.md file to better describe scope.
Merge pull request #209 from ismaelga/attributes_with_keys

Able to specify keys on the attributes method
Merge pull request #172 from vladson/patch-1

Added description of default_serializer_options to README.md. Fixes #168
Merge pull request #167 from GateGuru/feature/specify-association-serializers-as-strings

Add support for specifying the serializer for an association as a String...