added lexer tests from group4 DerCompiler

See merge request !14

Linter

See merge request !16

Add cow-based tests

See merge request !17

Also change line endings from CRLF to LF

Add test for a large integer literal (1401 digits)

See merge request !13

Add weird number tests

See merge request !15

Introduce Flammenwehrfer

See merge request !9

Make int-literal-with-leading-zero test valid and add out file.

See merge request !11

Gruppe 5: Lexer tests

See merge request !7

Add haskell and dollar identifier

See merge request !6

Add super simple test cases for lexer

See merge request !5

add basic lexer tests

See merge request !4

1. Almost Keywords: Keywords with an extra trailing character, resulting in identifiers
2. Integer Literal with leading zero: Must fail according to spec
3. Uppercase Keywords: Keywords must be lexed case-sensitive
4. Waffelrezept: (slightly modified from https://www.chefkoch.de/rezepte/662351168076093/Geheimes-Waffelrezept.html)
5. Wild Whitespaces: A bit code in a mix of whitespaces

1) It is fun to see how much of a different language you can embed
2) This revealed a part in our lexer where we were too permissive

Fix maven cache repository path

See merge request !8

Previously the cache expected "repository" but it was set to
".repository", causing unnecessary maven dependency downloads.