A couple README fixes (#105)
A couple README fixes (#105)

- Remove the hdf5-dev requirement from Linux instructions (no longer necessary), but add ssl-dev.
- Fix a '=' in a build.yml example.
- URLs don't work in code blocks, so remove the silly-looking `[` and `]` in build.yml
quiltdata/quilt-compiler,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt-compiler,quiltdata/quilt-compiler,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt-compiler