Optimizing MySQL 5.6 for unit tests
the innodb_log_file_size looks rather small for what I assume is bulk loaded  unit test data with lots of writes.

A decent innodb_buffer_pool_size needs to be set that accounts for the active test size.

Because crash safety isn't a concern, like innodb_doublewrite=0  innodb_flush_log_at_trx_commit=0, will speed up write transactions.

max_connections implies you are doing multithreaded clients and if those are connecting/disconnecting maybe set thread_cache_size to the maximum number typically used.

A SHOW GLOBAL STATUS after a test run might give a hint as to what other aspects could be tuned.