Add tests to CMake project

Related to https://github.com/xiph/vorbis/issues/73.

Signed-off-by: Ralph Giles <giles@thaumas.net>
2 jobs for cmake in 1 minute and 45 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #10947
docker
autoconf

00:01:45

passed #10948
docker
cmake

00:00:36