Unify GWM, modules args/kwargs

[codecov-io]

Codecov Report

Merging #368 into master will increase coverage by 1.34%. The diff coverage is 88.55%.

@@            Coverage Diff             @@
##           master     #368      +/-   ##
==========================================
+ Coverage   85.07%   86.41%   +1.34%     
==========================================
  Files         220      220              
  Lines       10490    10592     +102     
==========================================
+ Hits         8924     9153     +229     
+ Misses       1566     1439     -127

[corochann]

Take over from

• https://github.com/pfnet-research/chainer-chemistry/pull/343
• https://github.com/pfnet-research/chainer-chemistry/issues/367

Direction

• Refactored to Implement all GWM models in gwm level modules. GWMGraphConvModel supports many types of combination, but we may not support all combination.
• Refactored args/kwargs to use common name for all model implementations.