session_duration <= 0 should be ignored

[jboehle]

When working on the Countly Android SDK, I fixed some issues that will stop the Android client from sending negative session_duration values to the server. However, due to existing SDK clients in the wild that may never be updated, the server should protect against negative session_duration values infiltrating the server database.

I believe this is related to the issue in support forums here.

[jboehle]

This bug also causes some other bad data to be inserted into the database. It can cause 'null' to be added to 'meta.d-ranges', and it can cause 'undefined' to be added to .ds dictionaries.

I have committed a fix for this to my fork by checking for undefined calculatedDurationRange in the processSessionDurationRange method in usage.js and if it's undefined, don't update the 'sessions' collection.

I've also added to the bin/updateCollections.js script to clean up some of the bad data that this bug has created, please take a look and let me know what you think.

[ar2rsawseen]

This was fixed in 4dc18b8