Remove test that causes nix build to fail

dyesub-tool/src/render.rs

@@ -63,13 +63,3 @@ pub fn render(input: &str) -> Result<String> {
     };
     Ok(document.render()?)
 }
-
-#[cfg(test)]
-mod tests {
-    use super::render_file;
-
-    #[test]
-    fn render() {
-        render_file("layout.json", "output.svg").unwrap();
-    }
-}