Changes in version 1.2.1 (2019-08-04)                  

  - fix bug
      - column names are broken using non-standard name in tibble
      - makedummies() converts 'NA' to '0'

                 Changes in version 1.2.0 (2019-03-03)                  

  - add S3 methods
      - matrix class data is automatically converted to data.frame class
      - return tibble class when data is tibble
  - fix several bugs
      - return rownames of input data

                 Changes in version 1.1.2 (2018-07-28)                  

  - fix several bugs
      - the column names are inappropriate.
      - the columns are droped when they contain only one level.

                 Changes in version 1.1.1 (2018-06-23)                  

  - Pull Request #1 "add column name when when columns has binary value"
    (https://github.com/toshi-ara/makedummies/pull/1) Thanks to Kohki
    YAMAGIWA for the contribution.

                  Changes in version 1.1 (2018-04-06)                   

  - makedummies() accepts a tbl class data.
  - fixed bug when "POSIXt" class is included.