Fix typos in README
Merge pull request #530 from deejay1/string_fixes

Fix typos in README
Passing is_master flag through on reset

 - is_master is not passed through when recreating the ConnectionPool.
 - This was causing unexpected behaviour where we would specifiy that we
   wish to connect to the slave, but the master would be read from
   instead.
Merge pull request #534 from df3n5/master

Sentinel connection pool discarding is_master flag on reset
should also reinitialize with check_connection