How can I get MySQL to accept both resume and resumé on a primary key?
It seems that MySQL does not support Accent Sensitive collations. (See http://dev.mysql.com/doc/refman/5.6/en/charset-collation-implementations.html) 

Therefore your only option is to go with a binary collation, e.g. utf8_bin. However, that would also make the column case sensitive, which is different from your current collation.

See also https://stackoverflow.com/questions/500826/how-to-conduct-an-accent-sensitive-search-in-mysql