PyPi release 1.6.1

Minor point release.

Release notes:

In the core.ermrest_model module:

• Table.define() changes to have more human readable annotated names of system columns;
• Table.define_asset() changes to use Filename as row_name and change hatrac_template to be multi-catalog friendly;
• New Table.define_page() defines a wiki page like table definition;
• New Schema.define_www() defines a wiki like schema with page and related file (asset) tables;
• New Model.configure_baseline_ermrest_client() gives ERMrest_Client more user-friendly annotations;
• New Model.configure_baseline_ermrest_group() gives ERMrest_Group more user-friendly annotations;
• New Model.configure_baseline_catalog() creates WWW schema, configures the ERMrest client and group tables, and defines an initial chaise-config annotation including a navigation bar menu.

In the (new) config.examples package data:

• New self_serve_policy.json template for use with deriva-acl-config for a simple self-service (row creator can edit) policy;
• New group_owner_policy.json template that builds on the self_serve_policy.json template to add policy statements for tables that have an Owner column and accompanying foreign key reference to the ERMrest group table.