Make namespaces internals private

Author: Tko1

src/environment.rs

@@ -527,11 +527,7 @@ mod tests {
                     curr_ns_sym: _,
                     namespaces,
                 }) => namespaces
-                    .0
-                    .borrow()
-                    .get(&Symbol::intern("user"))
-                    .unwrap()
-                    .get(&Symbol::intern("+")),
+                    .get(&Symbol::intern("user"),&Symbol::intern("+")),
                 _ => panic!("new_main_environment() should return Main"),
             };
 

src/namespace.rs

@@ -30,7 +30,7 @@ impl Namespace {
     }
 }
 #[derive(Debug, Clone)]
-pub struct Namespaces(pub RefCell<HashMap<Symbol, Namespace>>);
+pub struct Namespaces(RefCell<HashMap<Symbol, Namespace>>);
 
 impl Namespaces {
     pub fn new() -> Namespaces {