Fix some typos

sinatra-contrib/lib/sinatra/config_file.rb

@@ -70,7 +70,7 @@ module Sinatra
   #
   # But it also can provide specific environment configuration.  There are two
   # ways to do that: at the file level and at the setting level.  They are
-  # illustrated, repsectively, as follows:
+  # illustrated, respectively, as follows:
   #
   #     development:
   #       foo: development

sinatra-contrib/lib/sinatra/streaming.rb

@@ -6,7 +6,7 @@ module Sinatra
   # = Sinatra::Streaming
   #
   # Sinatra 1.3 introduced the +stream+ helper. This addon improves the
-  # streaming API by making the stream object immitate an IO object, turning
+  # streaming API by making the stream object imitate an IO object, turning
   # it into a real Deferrable and making the body play nicer with middleware
   # unaware of streaming.
   #