Add created_at and created_by columns to series_sales table and fill them with default values.

Author: cssru

.travis.yml

@@ -7,6 +7,15 @@ env:
   global:
     - secure: "fBav56BzY+A+Vs1g9YSfo1oLDCO1rFrXl49lJkOA5/XpnsKEEs4lI2RcOzz0wiJKXFNgcliiAJWoYMI8Esqz+lkyFWan4ij5Co0UzJcytDuY+2o+jaqwx45DuDYPogABzT+hWjLCxQLLG46gUkChzT8kcvOOn6JxC7Ff8q5MnoM="
 
+dist: trusty
+sudo: required
+addons:
+  apt:
+    packages:
+    - mysql-server-5.6
+    - mysql-client-core-5.6
+    - mysql-client-5.6
+    
 before_script:
   - if [ "$SPRING_PROFILES_ACTIVE" = 'travis' ]; then
       mysql -u travis -e 'CREATE DATABASE mystamps CHARACTER SET utf8;';