Fix the build test (#16)
Fix the build test (#16)

- Use QuiltTestCase so tests run in a new temporary directory
- Use different usernames for the two tests so module imports aren't cached
quiltdata/quilt-compiler,quiltdata/quilt,quiltdata/quilt-compiler,quiltdata/quilt,quiltdata/quilt-compiler,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt-compiler