Modernize code and address security issues

Minor release

• Update libraries to address security-warnings
• Update event handling to adhere to CanJS standards
• Switch test-runner from Testee to Karma
• Modernize code

Add Ability to Specify Arrows

• carouselOptions now allows one to specify the image to be used for left and right arrows:

navArrows: {
    leftSvgUrl: `/src/assets/icons.svg#pointLeft`,
    rightSvgUrl: `/src/assets/icons.svg#pointRight`
}

• updates to unit tests, some refactoring of internal code

Breaking changes

change

<div class="block slide {{#is ../activeSlideIndex scope.index}} active {{/is}}"
...

to

<div class="block slide {{#is ../activeSlideIndex scope.index}} active {{/is}} slide{{scope.index}}" 
...

in the stache file that is importing the tucows-donejs-carousel

Fix Unclickable Anchor Tags

• fix problem where only anchor tags on the last slide were clickable by adding z-index to each slide

Add Fade Transition

• add new option for a fade transition by specifying transition: 'dissolve' in carouselOptions
• new demo page for developers which shows 8 different carousels with different carouselOptions specified
• reworked unit tests

Fix Deprecation Warnings

• modify %event and %index to scope.event and scope.index
• update node version to lts (v10.x) in travis.yml (tests were failing on v11)