* Fixed memory leak with inactive tabs

* Minor fix

* Moved inacitve tab memory leak fix

* Rolled up build files

closes #2558 
closes #2057 

* Fix selected api not working.
d3 selection changed in V4, now returning object not array.
.nodes() can be called to return array from selection object.

Signed-off-by: liaan <liaan@jerichosystems.co.za>

* Removed merge and unnecessary map.

Signed-off-by: liaan <liaan@jerichosystems.co.za>

* Fix selected api not working.
d3 selection changed in V4, now returning object not array.
.nodes() can be called to return array from selection object.

Signed-off-by: liaan <liaan@jerichosystems.co.za>

* Removed swap file

Signed-off-by: liaan <liaan@jerichosystems.co.za>

* Implemented basic selected api test in drag functionality tests.

Signed-off-by: liaan <liaan@jerichosystems.co.za>

* Added test for selected with targetId filter

Signed-off-by: liaan <liaan@jerichosystems.co.za>

Default value of multiline is `false` on document.

https://c3js.org/reference.html#axis-x-tick-multiline

But, Default value of multiline is `true` on code.

https://github.com/c3js/c3/blob/master/src/config.js#L57

This reverts commit 89ef1088.

* chore(package): update karma to version 4.0.1

* chore(package): update lockfile package-lock.json

* chore(package): update nodemon to version 1.18.10

* chore(package): update lockfile package-lock.json

* chore(package): update rollup to version 1.0.0

* chore(package): update lockfile package-lock.json

* chore(package): update nodemon to version 1.18.9

* chore(package): update lockfile package-lock.json

* chore(package): update karma to version 3.1.4

* chore(package): update lockfile package-lock.json

* chore(package): update rollup to version 0.68.0

* chore(package): update lockfile package-lock.json

* chore(package): update jshint to version 2.9.7

* chore(package): update lockfile package-lock.json

* Fixed chart height determination issue number 2467

* Added sample resize.html

* chore(package): update karma-browserify to version 6.0.0

* fix(ci): change cache key

* chore: update package-lock.json

* chore(package): update rollup to version 0.67.0

* chore(package): update lockfile package-lock.json

Options for the type of spline interpolation methods aren't documented -- or at least I couldn't find it in docs. Option was added with #1268

`document.hidden` is available on supported browsers.

closes #2494 

* chore(package): update gh-pages to version 2.0.0

* chore(package): update lockfile package-lock.json

* chore(package): update rollup to version 0.66.0

* chore(package): update lockfile package-lock.json