Correcting some imports. By doing so, I have also broken the __main__.py

that was living in parser.py but repl.py is now usable :) The old tests
should probably be moved in the tests folder.

ziffers/mapper.py

@@ -1,7 +1,7 @@
-from lark import Lark, Transformer
-from classes import *
-from common import flatten
-from defaults import default_durs
+from lark import Transformer
+from .classes import *
+from .common import flatten
+from .defaults import default_durs
 from collections import Counter
 
 class ZiffersTransformer(Transformer):

ziffers/parser.py

@@ -1,5 +1,5 @@
 from rich import print
-from mapper import *
+from .mapper import *
 from pathlib import Path
 from lark import Lark