added .gitignore
Merge branch 'master' of https://github.com/janizde/WP-Opening-Hours

# By Florian Schlittenbauer
# Via Florian Schlittenbauer (1) and Jannik Portz (1)
* 'master' of https://github.com/janizde/WP-Opening-Hours:
  [BUGFIX] Remove PHP errros