Date validity check on User Story 'date' property missing

[arturonuman]

Steps to reproduce it:

• Making use of an existing User Story JSON file, modify the 'date' property to be on year 9999
• Reload the dashboard's home page.

Expected Behaviour:

• Date validity check should include lower and upper bounds in the year.
• Created date should always be lower or equal to the Last Update date.
• The invalid date should be displayed in the Date Created column with a warning note letting the user know the issue.

Actual Behaviour:

• Year 0000 and 9999 are allowed.
• Created date can be set to be higher than the Last Update date.

[viridianaJazel]

"Created date should always be lower or equal to the Last Update date."
Let change it to just lower, it could be possible that a blueprint is updated the same day it was created it

[viridianaJazel]

PR #19