test(task): Add format for comparing Values

After upgrading to minijinja 2.3.0, this fails:
```
    #[test]
    fn test_minijinja() {
        let vars = context! {};
        let new_vars = context! {..vars.clone()};
        assert_eq!(vars, new_vars);
  }
```

Signed-off-by: Alexander Gil <[email protected]>

rash_core/src/task/mod.rs

@@ -741,7 +741,7 @@ mod tests {
         let expected = context! {
             item => 3,
         };
-        assert_eq!(result, expected);
+        assert_eq!(format!("{}", result), format!("{}", expected));
     }
 
     #[test]
@@ -790,7 +790,7 @@ mod tests {
 
         let vars = context! {};
         let result = task.exec(vars.clone()).unwrap();
-        assert_eq!(result, vars);
+        assert_eq!(format!("{}", result), format!("{}", vars));
     }
 
     #[test]
@@ -805,8 +805,7 @@ mod tests {
 
         let vars = context! {buu => "boo"};
         let result = task.exec(vars.clone()).unwrap();
-        assert_eq!(result, vars);
-
+        assert_eq!(format!("{}", result), format!("{}", vars));
         let s0 = r#"
             name: task 1
             debug:
@@ -818,7 +817,7 @@ mod tests {
 
         let vars = context! {buu => "boo"};
         let result = task.exec(vars.clone()).unwrap();
-        assert_eq!(result, vars);
+        assert_eq!(format!("{}", result), format!("{}", vars));
     }
 
     #[test]