Small typo fix in doc.

Author: peter50216

lib/concurrent/async.rb

@@ -142,7 +142,7 @@ module Concurrent
   # practice is to read the instance variable into a local variable at the start
   # of the method then update the instance variable at the *end* of the method.
   # This way, should an exception be raised during method execution the internal
-  # state of the boject will not have been changed.
+  # state of the object will not have been changed.
   #
   # ### Reader Attributes
   #

lib/concurrent/atom.rb

@@ -19,7 +19,7 @@
 #     the value will undergo frequent reads but only occasional, though complex,
 #     updates. Suitable when the result of an update must be known immediately.
 #   * *{Concurrent::AtomicReference}:* A simple object reference that can be
-#     atomically. Updates are synchronous but fast. Bast used when updates a
+#     atomically. Updates are synchronous but fast. Best used when updates a
 #     simple set operations. Not suitable when updates are complex.
 #     {Concurrent::AtomicBoolean} and {Concurrent::AtomicFixnum} are similar
 #     but optimized for the given data type.