MAINT: Fix cargo-release setting for tag name

We used plain "1.0.0" as the tag name before, the default in cargo
release changed to "v1.0.0" now.

Unsure what the best course is - v prefix seems best, but existing tags
are without. So configure for no prefix.

Author: bluss

Cargo.toml

@@ -52,6 +52,7 @@ debug = true
 
 [package.metadata.release]
 no-dev-version = true
+tag-name = "{{version}}"
 
 [package.metadata.docs.rs]
 features = ["serde-1", "rayon"]