[ENH] add method dispatch
[NEW] requirement breakdown
[ENH] allow to import from __init__ in spec module
Merge pull request #31 from htkm/enh/api-exposure-tokyo-metro

[ENH] allow to import from __init__ in spec module
Merge pull request #32 from htkm/new/method-dispatch

[ENH UTIL] add method dispatch
Merge pull request #33 from htkm/new/requirements-rtd

[NEW] requirement breakdown