Add dbapimaster builds to tox.ini

For the Jenkins dbapi-master build, we can no longer
put git URLs in a constraints file, so just use tox.ini
itself to provide alternate dependencies.

Change-Id: Id6b53c511954ec31371810da85eea7b5a58dbc0d

Author: zzzeek

tox.ini

@@ -22,21 +22,32 @@ deps=
      greenlet != 0.4.17
      mock; python_version < '3.3'
      importlib_metadata; python_version < '3.8'
+
      postgresql: .[postgresql]
      postgresql: .[postgresql_asyncpg]; python_version >= '3'
      postgresql: .[postgresql_pg8000]; python_version >= '3'
+
      mysql: .[mysql]
      mysql: .[pymysql]
      mysql: git+https://github.com/sqlalchemy/aiomysql@sqlalchemy_tox; python_version >= '3'
      mysql: .[mariadb_connector]; python_version >= '3'
 
-     # we should probably try to get mysql_connector back in the mix
-     # as well
-     # mysql: .[mysql_connector]; python_version >= '3'
-
      oracle: .[oracle]
+
      mssql: .[mssql]
 
+     dbapimaster-postgresql: git+https://github.com/psycopg/psycopg2.git@master#egg=psycopg2
+     dbapimaster-postgresql: git+https://github.com/MagicStack/asyncpg.git#egg=asyncpg
+     dbapimaster-postgresql: git+https://github.com/tlocke/pg8000.git#egg=pg8000
+
+     dbapimaster-mysql: git+https://github.com/PyMySQL/mysqlclient-python.git@master#egg=mysqlclient
+     dbapimaster-mysql: git+https://github.com/PyMySQL/PyMySQL.git@master#egg=pymysql
+     dbapimaster-mysql: git+https://github.com/mariadb-corporation/mariadb-connector-python@master#egg=mariadb
+
+     dbapimaster-oracle: git+https://github.com/oracle/python-cx_Oracle.git@master#egg=cx_Oracle
+
+     dbapimaster-mssql: git+https://github.com/mkleehammer/pyodbc.git@master#egg=pyodbc
+
      cov: pytest-cov
 
 allowlist_externals=sh