remove validation on sqlite database file extension

[danvergara]

Remove validation on sqlite database file extension

Description

It is up to the user to provide a valid file no matter the extension

Fixes #211

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Copy the existing dblab.db file with a new extension and ran dblab against it.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have checked my code and corrected any misspellings