Update grunt-jsdoc dependency to 2.2 to fix jsdoc issues in node 8.5 and later

[ialarmedalien]

The various tasks involving jsdoc fail on Node v8.5 and later:

Running "jsdoc:dist" (jsdoc) task
>> fs.js:1910
>>   binding.copyFile(src, dest, flags);
>>           ^
>> 
>> Error: EISDIR: illegal operation on a directory, copyfile '/dc-js/node_modules/ink-docstrap/template/static/fonts/glyphicons-halflings-regular.eot' -> 'web/docs/html/fonts'
>>     at Object.fs.copyFileSync (fs.js:1910:11)
[...]
Warning: jsdoc terminated with a non-zero exit code Use --force to continue.

The issue is concerned with relative and absolute paths, and has been fixed in jsdoc v3.5.5. The grunt-jsdoc plugin has been updated accordingly.

Bumping the version of grunt-jsdoc to ~2.2.0 in package.json enables the grunt tasks to complete successfully.

[gordonwoodhull]

Thanks @ialarmedalien!

I was able to confirm this. While I was at it, I updated the rest of the outdated dependencies, according to gemnasium, and everything appears to work fine. (Except for d3v4, of course, that's a long haul.)

I've pushed to develop and I'm waiting for travis to complete. I'll push this as part of the next release.

Ran into some odd nodejs dependency problems along the way. In case anyone else runs into this, for some reason I had to manually install are-we-there-yet and gauge at the same time. Some kind of circular dependency I guess.

[gordonwoodhull]

This was fixed in 1f59a59