Bump version to 1.3.4

Bumps version 1.3.2 -> 1.3.3

Adds `wp_kses_post` to changelog output in Updater class.

Bumps version 1.3.0 -> 1.3.1

Removes error_log from Updater class

Updates to v1.2.1. Introduces Updater class for auto-updates and upda…

…tes namespace to use common GravityForms path.