1.2.0
 - The function "make_period" has been added.
 - The argument "timeout" has been added to main functions.
 - The function "all_tables" has been entirely rewritten.
 - Examples have been modified to pass the automated checking of CRAN. The reason of such changes is unstable responses from the NSO server.

1.1.0
 - The error handling feature has been added due to a HTTP 500 error on the NSO server.
 - The new argument "simplify" has been added to the function "get_table_info". A user-friendly value is returned by using this new argument.

1.0.0
 - Initial release
