Add tests to CMake project

Related to https://github.com/xiph/vorbis/issues/73.
2 jobs for cmake-add-tests in 1 minute and 46 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed autoconf #10941
docker

00:01:46

failed cmake #10942
docker

00:00:30

 
Name Stage Failure
failed
cmake Build
[29/29] Linking C executable test/vorbis_test
FAILED: test/vorbis_test
: && /usr/bin/cc -O3 -DNDEBUG -rdynamic test/CMakeFiles/vorbis_test.dir/util.c.o test/CMakeFiles/vorbis_test.dir/write_read.c.o test/CMakeFiles/vorbis_test.dir/test.c.o -o test/vorbis_test lib/libvorbis.a /usr/lib/x86_64-linux-gnu/libogg.so -lm && :
/usr/bin/ld: test/CMakeFiles/vorbis_test.dir/write_read.c.o: in function `write_vorbis_data_or_die':
write_read.c:(.text+0x5e): undefined reference to `vorbis_encode_init_vbr'
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.
Cleaning up file based variables
ERROR: Job failed: exit code 1