Bump the tested version of MySQL Connector.

When we updated PyPy on Travis to 5.8.0, it started producing errors
"Use multi-True when executing multiple statements", even when we are
demonstrably only executing one statement. E.g.,
https://travis-ci.org/zodb/relstorage/jobs/335720512#L923

If this doesn't fix it, then I plan to take PyPy+MySQL Connector out
of the test matrix.

.travis/setup-cmysqlconnector.sh

@@ -1,6 +1,6 @@
-wget https://dev.mysql.com/get/Downloads/Connector-Python/mysql-connector-python-2.1.5.tar.gz
-tar -xf mysql-connector-python-2.1.5.tar.gz
-cd ./mysql-connector-python-2.1.5
+wget https://dev.mysql.com/get/Downloads/Connector-Python/mysql-connector-python-8.0.6.tar.gz
+tar -xf mysql-connector-python-8.0.6.tar.gz
+cd ./mysql-connector-python-8.0.6
 python ./setup.py install --with-mysql-capi=/usr
 cd ..
 python -c 'import relstorage.adapters.mysql.drivers as D; print(D.preferred_driver_name,D.driver_map)'

.travis/setup-mysqlconnector.sh

@@ -1,3 +1,3 @@
-pip install https://dev.mysql.com/get/Downloads/Connector-Python/mysql-connector-python-2.1.5.tar.gz
+pip install https://dev.mysql.com/get/Downloads/Connector-Python/mysql-connector-python-8.0.6.tar.gz
 python -c 'import relstorage.adapters.mysql.drivers as D; print(D.preferred_driver_name,D.driver_map)'
 `dirname $0`/mysql.sh

CHANGES.rst

@@ -10,6 +10,8 @@
   CFFI compilation environment. Fixes :issue:`187`, reported by
   Johannes Raggam.
 
+- Test with MySQL Connector/Python 8.0.6, up from 2.1.5.
+
 
 2.1a2 (2017-04-15)
 ==================

doc/install.rst

@@ -41,7 +41,7 @@ database.
 
 On CPython2, install psycopg2 2.6.1+, mysqlclient 1.3.7+, or cx_Oracle
 5.2+ (but use caution with 5.2.1+); PyMySQL 0.7, MySQL
-Connector/Python 2.1.5 and umysql are also known to work as is pg8000.
+Connector/Python 8.0.6 and umysql are also known to work as is pg8000.
 
 For CPython3, install psycopg2, mysqlclient or cx_Oracle;
 PyMySQL, MySQL Connector/Python  and pg8000 are also known to work.