Fix: Import HashMap instead of Map

I didn't catch that when merging PR #217.

Fixes: be82af2 ("Rename MapImpl to Map")
Fixes: 0d3a5c3 ("Merge pull request #217 from dlo9/master")
Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

Author: matthiasbeyer

examples/simple/src/main.rs

@@ -1,4 +1,4 @@
-use std::collections::Map;
+use std::collections::HashMap;
 
 fn main() {
     let mut settings = config::Config::default();
@@ -9,7 +9,7 @@ fn main() {
         // Eg.. `APP_DEBUG=1 ./target/app` would set the `debug` key
         .merge(config::Environment::with_prefix("APP")).unwrap();
 
-    // Print out our settings (as a Map)
+    // Print out our settings (as a HashMap)
     println!("{:?}",
-             settings.try_into::<Map<String, String>>().unwrap());
+             settings.try_into::<HashMap<String, String>>().unwrap());
 }