Bump html5ever to 0.26

Author: cfvescovo

Cargo.toml

@@ -18,7 +18,7 @@ readme = "README.md"
 [dependencies]
 cssparser = "0.27"
 ego-tree = "0.6"
-html5ever = "0.25.1"
+html5ever = "0.26"
 matches = "0.1.6"
 selectors = "0.22"
 smallvec = "1"