Remove get_mixables function from mixable_holder
Remove get_mixables function from mixable_holder

kmaehashi/jubatus_core,gintenlabo/jubatus_core,kmaehashi/jubatus_core,gintenlabo/jubatus_core,kumagi/jubatus_core,gintenlabo/jubatus_core,kmaehashi/jubatus_core,rimms/jubatus_core,kumagi/jubatus_core,rimms/jubatus_core,kmaehashi/jubatus_core,rimms/jubatus_core,kumagi/jubatus_core,kumagi/jubatus_core,rimms/jubatus_core,gintenlabo/jubatus_core