Update README.md

extra-credit/hw4-ec/README.md

 # Extra Credit. Bloom Filter
 This homework assignment introduces an advanced use of hashing called a Bloom filter. 
 
-Due Date: *Friday May 21, 11:59 pm*
+Due Date: *June 3rd, 11:59 pm*
 
 ## Initial Setup
 Before you start an assingment you should sync your cloned repository with the online one: