Upgrading svgbob 0.6.{5 → 6} breaks svgbobdoc

[yvt]

https://docs.rs/crate/r3/0.2.0/builds/526363

error[E0599]: no method named `text` found for reference `&Node<&str, &str, svgbob::sauron::prelude::Leaf, &str, AttributeValue<()>>` in the current scope
   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/svgbobdoc-0.3.0-alpha.4/src/textproc.rs:297:47
    |
297 |                     if let Some(text) = child.text() {
    |                                               ^^^^ method not found in `&Node<&str, &str, svgbob::sauron::prelude::Leaf, &str, AttributeValue<()>>`

(edit: This particular breakage was fixed by #4)

[yvt]

Pinning svgbob to a specific version (e.g., 0.6.5) will permanently resolve the issue. Pinning is also beneficial for maintaining stable rendering results, since It's hard to imagine that this is covered by semver guarantees, though pinning may negatively impact compilation times on the user's end and impede the application of bug fixes. I wonder if @ivanceras could provide some guidance on this.