Update utils __init__.py to include chunk_list() (#608)

Author: BioCam

pylabrobot/utils/__init__.py

@@ -1,3 +1,3 @@
-from .list import assert_shape, reshape_2d
+from .list import assert_shape, chunk_list, reshape_2d
 from .object_parsing import find_subclass
 from .positions import expand_string_range