Update "wp-evidence-hub" submodule/WP Plugin from 3 March to 16 April

* 3 March: https://github.com/mhawksey/wp-evidence-hub/commit/f42fa65639b8fb04
* 16 Apr: https://github.com/mhawksey/wp-evidence-hub/commit/e666a787d3fbc379
* By @mhawksey "Fix CSS for wordpress 3.9 compatibility"