Update pod spec to include `swift` files According to https://github.com/ResearchKit/ResearchKit/pull/383#issuecomment-161036351
Update pod spec to include `swift` files
According to
https://github.com/ResearchKit/ResearchKit/pull/383#issuecomment-161036351

md0u80c9/ResearchKit,boland25/ResearchKit,jeremiahyan/ResearchKit,weijentu/ResearchKit,allen7wang/ResearchKit,weijentu/ResearchKit,weijentu/ResearchKit,oliverschaefer/ResearchKit,oliverschaefer/ResearchKit,chb/ResearchKit,weijentu/ResearchKit,chb/ResearchKit,mluedke2/ResearchKit,KaiCode2/ResearchKit,allen7wang/ResearchKit,mluedke2/ResearchKit,YuanZhu-apple/ResearchKit,mluedke2/ResearchKit,YuanZhu-apple/ResearchKit,oliverschaefer/ResearchKit,oliverschaefer/ResearchKit,md0u80c9/ResearchKit,shazino/ResearchKit,YuanZhu-apple/ResearchKit,cornelltech/ResearchKit,KaiCode2/ResearchKit,boland25/ResearchKit,shazino/ResearchKit,allen7wang/ResearchKit,chb/ResearchKit,cornelltech/ResearchKit,md0u80c9/ResearchKit,boland25/ResearchKit,shazino/ResearchKit,jeremiahyan/ResearchKit,md0u80c9/ResearchKit,chb/ResearchKit,YuanZhu-apple/ResearchKit,cornelltech/ResearchKit,boland25/ResearchKit,jeremiahyan/ResearchKit,KaiCode2/ResearchKit