The fifth annual Mustard Seed Spin was held yesterday on the American River Trail  with guest speaker Mayor Kevin Johnson showing his support for the need to take care of our children and keep what safety nets we do have in place from disappearing.  The fundraiser benefited Mustard Seed School for homeless children of all ages. The ride featured area kids riding for their less fortunate counter parts and showing grit riding in temperatures well  into the nineties.   The goodwill and the social responsibility on display was breathtaking not to mention the smiles on the young riders determined faces.   Mayor Johnson reminded us we all needed to step up and pitch in the best we can during