Upgrade database.

def upgrade():
    """Upgrade database."""
    op.create_table(
        'oauth2server_client',
        sa.Column('name', sa.String(length=40), nullable=True),
        sa.Column('description', sa.Text(), nullable=True),
        sa.Column(
            'website',
            sqlalchemy_utils.types.url.URLType(),
            nullable=True),
        sa.Column('user_id', sa.Integer(), nullable=True),
        sa.Column('client_id', sa.String(length=255), nullable=False),
        sa.Column('client_secret', sa.String(length=255), nullable=False),
        sa.Column(
            'is_confidential',
            sa.Boolean(name='is_confidential'),
            nullable=True),
        sa.Column(
            'is_internal',
            sa.Boolean(name='is_internal'),
            nullable=True),
        sa.Column('_redirect_uris', sa.Text(), nullable=True),
        sa.Column('_default_scopes', sa.Text(), nullable=True),
        sa.ForeignKeyConstraint(['user_id'], [u'accounts_user.id'], ),
        sa.PrimaryKeyConstraint('client_id')
    )
    op.create_index(
        op.f('ix_oauth2server_client_client_secret'),
        'oauth2server_client',
        ['client_secret'],
        unique=True
    )
    op.create_table(
        'oauth2server_token',
        sa.Column('id', sa.Integer(), nullable=False),
        sa.Column('client_id', sa.String(length=255), nullable=False),
        sa.Column('user_id', sa.Integer(), nullable=True),
        sa.Column('token_type', sa.String(length=255), nullable=True),
        sa.Column(
            'access_token',
            sqlalchemy_utils.EncryptedType(),
            nullable=True),
        sa.Column(
            'refresh_token',
            sqlalchemy_utils.EncryptedType(),
            nullable=True),
        sa.Column('expires', sa.DateTime(), nullable=True),
        sa.Column('_scopes', sa.Text(), nullable=True),
        sa.Column(
            'is_personal',
            sa.Boolean(name='is_personal'),
            nullable=True),
        sa.Column(
            'is_internal',
            sa.Boolean(name='is_internal'),
            nullable=True),
        sa.ForeignKeyConstraint(
            ['client_id'], [u'oauth2server_client.client_id'], ),
        sa.ForeignKeyConstraint(
            ['user_id'], [u'accounts_user.id'], ),
        sa.PrimaryKeyConstraint('id')
    )
    op.create_index(
        'ix_oauth2server_token_access_token',
        'oauth2server_token',
        ['access_token'],
        unique=True,
        mysql_length=255)
    op.create_index(
        'ix_oauth2server_token_refresh_token',
        'oauth2server_token',
        ['refresh_token'],
        unique=True,
        mysql_length=255)