Split API definitions to modules
Gather 'require' to constructor

There seems to be no explicit requirement for delayed loading.
Add specs for account, acl and user API
Remove redundunt '/' of PUT call path

It called 'https://api-import.treasuredata.com//v3/...
  //v3 -> /v3
Add BulkImport API spec
Add ServerStatus API
Spec file must have _spec.rb
Add Schedule API spec
Add Result API spec
Add Job API spec
Add Table API spec
Merge pull request #26 from treasure-data/topic_api_modules

API modules