Fix trap extension for source files without extensions

We were writing files with names like `Gemfile..trap.gz`. Now fixed to
`Gemfile.trap.gz`.

Author: nickrolfe

extractor/src/main.rs

@@ -40,8 +40,8 @@ impl TrapCompression {
 
     fn extension(&self) -> &str {
         match self {
-            TrapCompression::None => ".trap",
-            TrapCompression::Gzip => ".trap.gz",
+            TrapCompression::None => "trap",
+            TrapCompression::Gzip => "trap.gz",
         }
     }
 }
@@ -269,6 +269,7 @@ fn path_for(dir: &Path, path: &Path, ext: &str) -> PathBuf {
     }
     if let Some(x) = result.extension() {
         let mut new_ext = x.to_os_string();
+        new_ext.push(".");
         new_ext.push(ext);
         result.set_extension(new_ext);
     } else {