Additional python package requirements

[everittB]

Checklist of requirements to update python package:

• Ensure software license is selected
• Add additional test cases for rotate function
• Add additional test cases for mirror function
• Add additional test cases for translate function
• Update documentation, if required

[alyciakb]

Test that file path passed into functions leads to an actual file:

• Add FileNotFound error to rotate function test suite
• Add FileNotFound error to translate function test suite