/dev/pts/ptmx seems to be the only character special file in /dev
which is not a bind-mount in the docker container run by travis.
gnu stat does not detect these mounts, so produces a different
output for /dev/zero.
Updates to individual integration tests
- use proposed conventional approach to beginning tests
- use new convenience functions for using fixtures
- use new names for TestScenario
Updates to integration test modules
- add proposed conventional module-level functions
Updates to test/common/util.rs
- rename TestSet, and its methods, for semantic clarity
- create convenience functions for use of fixtures
- delete convenience functions obsoleted by new conventions
