1.5.0

• Improved pgbench API (see pgbench_run() etc);
• Set allow_streaming=True in init() and default_conf() by default;
• New option unix_sockets=True in init() and default_conf();
• Fixed base_dir ignore if provided base_dir does not exist (#31);
• StartNodeException now includes last N lines of postgresql.log;
• Improved exception handling (using six.raise_from);
• Auto name generation for PostgresNode (see generate_app_name);
• Provide compatibility mode for execute(), psql(), safe_psql() and poll_query_until() methods (see positional_args_hack);