Add missing dots for consistency with std docs

Signed-off-by: Wiktor Kwapisiewicz <wiktor@metacode.biz>

src/agent.rs

@@ -1,4 +1,4 @@
-//! Traits for implementing custom SSH agents
+//! Traits for implementing custom SSH agents.
 
 use std::fmt;
 use std::io;

src/codec.rs

@@ -1,4 +1,4 @@
-//! SSH agent protocol framing codec
+//! SSH agent protocol framing codec.
 
 use std::marker::PhantomData;
 use std::mem::size_of;

src/error.rs

@@ -1,4 +1,4 @@
-//! SSH agent errors
+//! SSH agent errors.
 
 use std::io;
 

src/proto.rs

@@ -1,4 +1,4 @@
-//! SSH agent protocol structures
+//! SSH agent protocol structures.
 
 pub mod error;
 pub mod extension;