[WIP] feat(aliby): instantiate Tiler object from dummy image

WHY IS THIS CHANGE NEEDED?:
- need a way to produce a dummy form of the next step after creating an
  image instance to test pipeline; this next step is the tiler

HOW DOES THE CHANGE SOLVE THE PROBLEM?:
- make template method

REFERENCES:
- issue #53

src/aliby/io/image.py

@@ -75,6 +75,7 @@ class BaseLocalImage(ABC):
         return self._rechunked_img
 
     @abstractmethod
+    # Should this function take Tiler parameters as an argument?
     def get_data_lazy(self) -> da.Array:
         """Return 5D dask array. For lazy-loading multidimensional tiff files. Dummy image."""
         examples_dir = get_examples_dir()

src/aliby/tile/tiler.py

@@ -247,6 +247,17 @@ class Tiler(StepABC):
 
         self.tile_size = self.tile_size or min(self.image.shape[-2:])
 
+    @classmethod
+    def from_dummy(cls, image, parameters: TilerParameters):
+        """
+        Instantiate Tiler from dummy image
+
+        Parameters
+        ----------
+        ...
+        """
+        pass
+
     @classmethod
     def from_image(cls, image, parameters: TilerParameters):
         """