Online-judge-tools

- [213](https://github.com/kmyk/online-judge-tools/issues/213) update the package on PyPI via Travis CI

- [210](https://github.com/kmyk/online-judge-tools/issues/210) fix a bug of `download` from AtCoder

- [208](https://github.com/kmyk/online-judge-tools/issues/208) features for HackerRank are removed
- [206](https://github.com/kmyk/online-judge-tools/issues/206) support the new `atcoder.jp` domain
- [202](https://github.com/kmyk/online-judge-tools/issues/202) write document
- [201](https://github.com/kmyk/online-judge-tools/issues/201) add `--json` option to `download` command

- [193](https://github.com/kmyk/online-judge-tools/issues/193) make languages selectable with their IDs with
- [198](https://github.com/kmyk/online-judge-tools/issues/198) suppress leading spaces of samples at Codeforces

- [193](https://github.com/kmyk/online-judge-tools/issues/193) fix an unintended behaviour of `--language` option of `submit` with `--guess` option; add some file extensions for Perl and Perl 6

- [188](https://github.com/kmyk/online-judge-tools/issues/188) fix a degression of `download` system cases of AOJ
- [194](https://github.com/kmyk/online-judge-tools/issues/194) use the official API of AOJ
- [196](https://github.com/kmyk/online-judge-tools/issues/196) support the beta version of AOJ