fix(db): Make using pg_service work again. When I did the merge of schema support I broke pg_service.conf support by replacing get_database_name with db_schema_split. This commit fixes it. Also this commit returns the schema if one is specified in pg_service.conf. back_postgresql.py: Replace calls to db_schema_split() with get_database_schema_names() (new name for get_database_name()). Rename db_schema_split to _db_schema_split. It now returns a tuple (dbname, schema) rather than a list. It is used only by get_database_schema_names() which also returns tuples. get_database_schema_names() can also get schema info for the service (if present) as specified by pg_service.conf. Add get_database_user() to get the user from either RDBMS_USER or pg_service.conf. (User needed for creating schema, so not needed before schema patch. import re at the top of file and remove lower import. Remove some schema code from db_command as it's not needed. The database conection is done to either postgresql or template1 existing databases. This command never connects to the roundp specified db. test/test_postgresql.py: Reorganize top level imports, add import os. Replace import of db_schema_split with get_database_schema_names. Also replace calls to db_schema_split. Create new Opener for the service file. Set PGSERVICEFILE to point to test/pg_service.conf. Add three new classes to test Service: 1) using regular db 2) using schema within db 3) Unable to parse schema name from pg_service.conf. The last doesn't need a db. Number 1 and 2 reuse the tests in ROTest to verify db connectivity. test/pg_service.conf: three service connections for: db only, db and schema, and incorrectly specified schema test cases. doc/upgrading.txt: updated to current status. Included example schema definition in service file.

"""
The following code was taken from:

    https://github.com/pytest-dev/pytest/issues/568#issuecomment-216569420

to resolve a bug with using pytest.mark.skip(). Once the bug is resolved in
pytest this file can be removed along with all the wrapper mark_class()
references in the other test files.
"""
import types


def mark_class(marker):
    '''Workaround for https://github.com/pytest-dev/pytest/issues/568'''
    def copy_func(f):
        try:
            return types.FunctionType(f.__code__, f.__globals__,
                                      name=f.__name__, argdefs=f.__defaults__,
                                      closure=f.__closure__)
        except AttributeError:
            return types.FunctionType(f.func_code, f.func_globals,
                                      name=f.func_name,
                                      argdefs=f.func_defaults,
                                      closure=f.func_closure)

    def mark(cls):
        if isinstance(cls, types.FunctionType):
            return marker(copy_func(cls))

        for method in dir(cls):
            if method.startswith('test'):
                f = copy_func(getattr(cls, method))
                setattr(cls, method, marker(f))
        return cls
    return mark