upgrade swagger-maven-plugin to 3.1.6-SNAPSHOT#21

azbarcea wants to merge 1 commit intokongchen:masterkongchen/swagger-maven-example:masterfrom

azbarcea:maven-plugin-3.1.6-SNAPSHOTazbarcea/swagger-maven-example:maven-plugin-3.1.6-SNAPSHOTCopy head branch name to clipboard