- adding diagonal option to kernel weights in user.py
Merge pull request #285 from sjsrey/diag

- adding diagonal option to kernel weights in user.py
- having build_lattice_shapefile also create the associated dbf file
- useful for testing our contiguity builders against geoda since dbf is
  required by the latter
Merge pull request #287 from sjsrey/lattice_shapefile

- having build_lattice_shapefile also create the associated dbf file
- deal with multiprocessing on travis
Merge pull request #304 from sjsrey/yaml_mp

- deal with multiprocessing on travis