Merge tag 'v1.0.28' into develop

Version 1.0.28

diff --cc classes/billingSupport.php
Simple merge

diff --cc index.php
index 9f2eda3,04719b2..c3774ec
--- 1/index.php
--- 2/index.php
+++ b/index.php
@@@ -37,8 -37,8 +37,8 @@@
   *  so that we're sure the other add-ons see an up to date
   *  version from this plugin.
   */
- define('GLM_MEMBERS_BILLING_PLUGIN_VERSION', '1.0.27');
+ define('GLM_MEMBERS_BILLING_PLUGIN_VERSION', '1.0.28');
 -define('GLM_MEMBERS_BILLING_PLUGIN_DB_VERSION', '0.0.26');
 +define('GLM_MEMBERS_BILLING_PLUGIN_DB_VERSION', '0.0.39');
  
  // This is the minimum version of the GLM Members DB plugin require for this plugin.
  define('GLM_MEMBERS_BILLING_PLUGIN_MIN_MEMBERS_REQUIRED_VERSION', '2.8.0');