The `ruma-common` crate is reexported by `ruma`, which is in our
dependency tree anyways. This change makes it so that qrcode, the only
crate that was making use of `ruma-common`, now depends on `ruma`. It
may move it further down the line in the compilation pipeline, but this
is unlikely to affect compile times in a crazy way. The benefit is that
this avoids the burden of having to specify the ruma commit hash twice
in the top-level Cargo.toml, as well as replacing it twice when
overriding it.
Benjamin Bouvier
d2feeaac30