upgrade vfsStream
upgrade vfsStream

 - mikey179/vfsstream updated from v1.6.5 to v1.6.6
   See changes: https://github.com/bovigo/vfsStream/compare/mikey179:v1.6.5...bovigo:v1.6.6
   Release notes: https://github.com/bovigo/vfsStream/releases/tag/v1.6.6

mikey179/bovigo-assert