Bump TUnit from 1.3.15 to 1.5.53 - #409

Process completed with exit code 2.

The variable 'e' is declared but never used

Converting null literal or possible null value to non-nullable type.

Converting null literal or possible null value to non-nullable type.

Converting null literal or possible null value to non-nullable type.

Converting null literal or possible null value to non-nullable type.

Converting null literal or possible null value to non-nullable type.

Non-nullable field 'Proxy' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'Proxy' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Dereference of a possibly null reference.