Solve day 9 part 1

Add build

Solve day 6 part 1, day 7 part 1

Move file reading functions to sub package, rename functions

and add SplitCommaToInt

Solve day 3 part 1

Move readFile to own package

day02: Fix test number

Solve day 2 part 2

Solve day 2 part 1

Add day01