Fix typo in README.rst

Author: roysmith

README.rst

@@ -17,7 +17,7 @@ Usage
 	from mwoauth import ConsumerToken, Handshaker
 	from six.moves import input # For compatibility between python 2 and 3
 	
-	# Consruct a "consumer" from the key/secret provided by MediaWiki
+	# Construct a "consumer" from the key/secret provided by MediaWiki
 	import config
 	consumer_token = ConsumerToken(config.consumer_key, config.consumer_secret)