Change: don't require mutable roadmap for get_step

In a previous version of the code, we got a step, theh modified it,
but no longer. Better this way.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/lib.rs b/src/lib.rs
index a5422ab..4b146f2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -130,8 +130,8 @@ impl Roadmap {
     }
 
     /// Get a step, given its name.
-    pub fn get_step<'a>(&'a mut self, name: &str) -> Option<&'a mut Step> {
-        for step in self.steps.iter_mut() {
+    pub fn get_step<'a>(&'a self, name: &str) -> Option<&'a Step> {
+        for step in self.steps.iter() {
             if step.name() == name {
                 return Some(step);
             }
@@ -261,7 +261,7 @@ first -> second;
 
     #[test]
     fn from_nonempty_yaml() {
-        let mut roadmap = Roadmap::from_yaml("
+        let roadmap = Roadmap::from_yaml("
 first:
   label: the first step
 second: