1.3.9 Maintenance Release

• Fix Invalid Pickup Intervals (#45)
• Fixes how the starting interval is set, especially during the middle of the current open/close pickup time.
• Sets end time 1 interval past it in order to have the end close pickup time be inclusive for pickup.
• Changes field title and help text for Pickup Days Ahead to be clear that the number does now represent the number of open days inclusive of the current day.
• Updates language files to handle some new dashboard labels and help text.
• Fixes incorrect use of pickup time interval instead of time delay. (#48)
• Updates version for 1.3.9 release.
• Changes direct WC_Order id attribute access to use get_id() method. (#49)
• Fixes incorrect time delay handling.
• Updates dependencies.
• Updates changelog and prepares for build.