Added max errand view logic

* User can only enter 3 errands
* wrote view helper method to change view if over 3 errands
Merge branch 'master' into max_3_errands
fixed merge conflict
did not assign @errands and fixed view
fixed merge conflicts
Merge pull request #35 from LightningLord/max_3_errands

Max 3 errands
resolved merge conflict
fixed bug in Trip#show to properly render errands