0.4.0

• Replaced Carbon Fields Loader dependency with official plugin
• Fixed non-static deprecation notice
• Added support for before/after strings to prefix()
• Added version check for wordpress-toolkit
• Added get_wpsac_plugin_option() example to Plugin class
• Updated JS injection to use wordpress-toolkit ScriptObject
• Added Customizer options example (via inc2734/wp-customizer-framework)
• Added various Carbon Fields custom CSS classes
• Bumped NPM dependency versions