Minor improvements to .travis.yml
Minor improvements to .travis.yml

robertibiris/RMDateSelectionViewController,nickoneill/RMDateSelectionViewController,scottphc/RMDateSelectionViewController,i-miss-you/RMDateSelectionViewController,CooperRS/RMDateSelectionViewController,zilaiyedaren/RMDateSelectionViewController,CooperRS/RMDateSelectionViewController,sandyway/RMDateSelectionViewController,jiamaozheng/RMDateSelectionViewController,kevin-hirsch/RMDateSelectionViewController,lijie121210/RMDateSelectionViewController,AlexanderMazaletskiy/RMDateSelectionViewController