solver submodule structure working again

python/damask/__init__.py

@@ -16,7 +16,7 @@ from ._lattice     import Symmetry, Lattice# noqa
 from ._orientation import Orientation      # noqa
 from ._result      import Result           # noqa
 from ._geom        import Geom             # noqa
-from ._solver      import Solver           # noqa
+from .             import solver           # noqa
 
 # deprecated
 from ._asciitable import ASCIItable       # noqa

python/damask/_solver/__init__.py

@@ -1,4 +0,0 @@
-"""Tools to control the various solvers."""
-
-from .solver   import Solver     # noqa
-from .marc     import Marc       # noqa

python/damask/solver/__init__.py

@@ -0,0 +1,3 @@
+"""Tools to control the various solvers."""
+
+from ._marc     import Marc       # noqa

python/damask/solver/_marc.py

@@ -3,7 +3,7 @@ import subprocess
 import shlex
 import string
 
-from .solver import Solver
+from ._solver import Solver
 import damask
 
 class Marc(Solver):