reuse predefined serializer instead of create new ones
Fix NPE when connected entity doesn't exist
add Rails compatibility information to README
Merge pull request #156 from usergrid/gridiron-doc-update

document Rails version compatibility
Merge pull request #152 from aweeraman/USERGRID-18

Fix and test for USERGRID-18
Merge pull request #147 from stliu/serializer

reuse predefined serializer instead of create new ones
Added license header.
Move Serializers class to correct package.
adding link directly to organization page
Merge pull request #158 from usergrid/add-organization-link

Add organization link
building files