[BUG] Duplicate entry for the last date in db while running Anomaly Detection daily

[Amatullah]

Describe the bug

While running Anomaly Detection daily for a KPI, we get a duplicate entry for the last date that is stored in the database.

Explain the environment

• Chaos Genius version: 0.1.3-alpha
• OS Version / Instance: AWS EC2
• Deployment type: setup from scratch

Current behavior

For example: we set up a KPI and for the first time and Anomaly Detection runs until Nov 23. Then next day when anomaly runs, we'll predict confidence intervals for Nov 24th but will also add the Nov 23rd entry again. The next day we predict for Nov 25th but also will add an entry for Nov 24th again and so on....

Expected behavior

Duplicate entries for the last date in the database should not exist.

Screenshots