cors 1.0.0

Cross-originresourcesharing(CORS)isgreat;itallowsyourvisitorsto asynchronouslyuploadfilestoe.g.FilepickerorAmazonS3,withoutthe fileshavingtoround-tripthroughyourwebserver.Unfortunately,giving youruserscompletewriteaccesstoyouronlinestoragealsoexposesyouto maliciousintent. Tocombatharmfulusage,gooduploadservicesthatallowclient-side upload,supportamechanismthatallowsyoutovalidateandsignallupload requeststoyouronlinestorage.Byvalidatingeveryrequest,youcangive yourvisitorsaniceuploadexperience,whilekeepingthebadvisitorsat bay. TheCORSgemcomeswithsupportfortheAmazonS3RESTAPI.