Adds support for GCLONE_FORCE_SSH env

src/git.rs

@@ -109,6 +109,12 @@ pub fn clone<P: AsRef<Path>>(url: &str, place: P) -> Result<()> {
     }
 }
 
+/// Rewrites an url to a SSH url.
+pub fn rewrite_url(url: &str) -> Result<String> {
+    let (server, owner, repo) = parse_url(url)?;
+    Ok(parse_to_url(&server, &owner, &repo))
+}
+
 /// Clones a git repository in the right place.
 fn clone_dirty<P: AsRef<Path>>(url: &str, place: P) -> Result<()> {
     let place = place.as_ref();
@@ -118,6 +124,12 @@ fn clone_dirty<P: AsRef<Path>>(url: &str, place: P) -> Result<()> {
         create_dir_all(parent)?;
     }
 
+    let url = if env::var("GCLONE_FORCE_SSH") == Ok("true".to_owned()) {
+        rewrite_url(url)?
+    } else {
+        url.to_owned()
+    };
+
     let command = Command::new("git")
         .args(&[
             "clone",