Added 2.5.0-preview1 definition

Add rbx-3.83 and rbx-3.84

`--quiet` option isn't sensible sha256sum(1) of GNU coreutils

The option is available only if verifying digest, not available when computing digest.

>       --quiet
>              don't print OK for each successfully verified file

Quote JRuby check on FreeBSD to avoid "unary operator" syntax issue.

Ignore everything after whitespace in the output from sha256sum

Add JRuby 9.1.13.0

The issue has originarily reported as pyenv/pyenv#902.

Unlike sha256sum of GNU coreutils, BusyBox one doesn't print '*'
and prints extra whitespaces, when computing digest from stdin.

sha256sum (GNU coreutils 8.26)

```
% cat /sbin/init | sha256sum -b
ef753e9504ada221155b86e7e6b7b4ff2499d64e27bcd959f0542bcac589feb1 *-
```

sha256sum (BusyBox v1.26.2)

```
/ # cat /sbin/init | sha256sum -b
4cd6d1a4028772fabc9166bb52b5826aec4e91874c107fce33dc515c04cb754f  -
```

I also confirmed that md5sum behaves just similarly.

Add mruby 1.3.0

Release:
https://github.com/mruby/mruby/releases/tag/1.3.0

Announcementns:
http://mruby.org/releases/2017/07/04/mruby-1.3.0-released.html

Closes #1106

Add JRuby 9.2.0.0 snapshot

Improve check for openssl on macOS

Add rbx-3.81 and rbx-3.82

Add definition for JRuby 9.1.11.0 and 9.1.12.0

http://jruby.org/2017/06/15/jruby-9-1-12-0.html

http://jruby.org/2017/06/14/jruby-9-1-11-0.html

Added gitignore for bats repository

invoke make update-gems before make install with ruby-trunk

- Only call `openssl version` once;

- Make the check work with future version of LibreSSL after 2.2.7. This
  assumes that Apple might keep updating LibreSSL shipping with macOS,
  but that they will never provide header files.