[WIP] Infrastructure + misc fixes and such.

[ryan-roemer]

A potpouri of fixes and updates for the underlying infrastructure.

Status

WIP - We have three test failures to fix:

Snapshot Summary
 › 3 snapshot tests failed in 1 test suite. Inspect your code changes or run with `yarn test -- -u` to update them.

Test Suites: 1 failed, 33 passed, 34 total
Tests:       3 failed, 61 passed, 64 total
Snapshots:   3 failed, 48 passed, 51 total

Changes

• Publish dist/spectacle.js and dist/spectacle.min.js as UMD bundles. Fixes webpack dist bundle has the wrong entry point #333
• Only publish specific files and bundles per whitelist .npmignore.
• Switch to npm version publishing workflow.
• Add CONTRINBUTING.md with COC and instructions for publishing.
• Travis: Use yarn, update node versions.
• Minor touchups:
  • Rename README.markdown to README.md since all other docs use that suffix.
  • Fix trailing commas in .babelrc
  • Add Travis CI badge.

Published file list

./dist/spectacle.js
./dist/spectacle.min.js
./docs/basic-concepts.md
./docs/extensions.md
./docs/getting-started.md
./docs/props.md
./docs/tag-api.md
./lib/actions/index.js
./lib/components/appear.js
./lib/components/block-quote.js
./lib/components/cite.js
./lib/components/clock.js
./lib/components/code-pane.js
./lib/components/code.js
./lib/components/component-playground.js
./lib/components/controls.js
./lib/components/deck.js
./lib/components/export.js
./lib/components/fill.js
./lib/components/fit.js
./lib/components/fullscreen.js
./lib/components/heading.js
./lib/components/image.js
./lib/components/layout.js
./lib/components/link.js
./lib/components/list-item.js
./lib/components/list.js
./lib/components/manager.js
./lib/components/markdown-slides.js
./lib/components/markdown.js
./lib/components/notes.js
./lib/components/overview.js
./lib/components/presenter-components.js
./lib/components/presenter.js
./lib/components/progress.js
./lib/components/quote.js
./lib/components/s.js
./lib/components/slide-set.js
./lib/components/slide.js
./lib/components/table-body.js
./lib/components/table-header-item.js
./lib/components/table-header.js
./lib/components/table-item.js
./lib/components/table-row.js
./lib/components/table.js
./lib/components/text.js
./lib/components/time-components.js
./lib/components/time.js
./lib/components/timer.js
./lib/components/transitionable.js
./lib/components/typeface.js
./lib/index.js
./lib/reducers/fragment.js
./lib/reducers/index.js
./lib/reducers/route.js
./lib/reducers/style.js
./lib/store/index.js
./lib/themes/default/codemirror.css
./lib/themes/default/dark.codemirror.css
./lib/themes/default/index.css
./lib/themes/default/index.js
./lib/themes/default/light.codemirror.css
./lib/themes/default/monokai.codemirror.css
./lib/themes/default/playground.css
./lib/themes/default/print.js
./lib/themes/default/screen.js
./lib/utils/base.js
./lib/utils/context.js
./lib/utils/controller.js
./lib/utils/playground.default-code.js
./lib/utils/preloader.js
./lib/utils/slides.js
./LICENSE
./package.json
./README.md
./src/actions/index.js
./src/components/appear.js
./src/components/block-quote.js
./src/components/cite.js
./src/components/clock.js
./src/components/code-pane.js
./src/components/code.js
./src/components/component-playground.js
./src/components/controls.js
./src/components/deck.js
./src/components/export.js
./src/components/fill.js
./src/components/fit.js
./src/components/fullscreen.js
./src/components/heading.js
./src/components/image.js
./src/components/layout.js
./src/components/link.js
./src/components/list-item.js
./src/components/list.js
./src/components/manager.js
./src/components/markdown-slides.js
./src/components/markdown.js
./src/components/notes.js
./src/components/overview.js
./src/components/presenter-components.js
./src/components/presenter.js
./src/components/progress.js
./src/components/quote.js
./src/components/s.js
./src/components/slide-set.js
./src/components/slide.js
./src/components/table-body.js
./src/components/table-header-item.js
./src/components/table-header.js
./src/components/table-item.js
./src/components/table-row.js
./src/components/table.js
./src/components/text.js
./src/components/time-components.js
./src/components/time.js
./src/components/timer.js
./src/components/transitionable.js
./src/components/typeface.js
./src/index.js
./src/reducers/fragment.js
./src/reducers/index.js
./src/reducers/route.js
./src/reducers/style.js
./src/store/index.js
./src/themes/default/codemirror.css
./src/themes/default/dark.codemirror.css
./src/themes/default/index.css
./src/themes/default/index.js
./src/themes/default/light.codemirror.css
./src/themes/default/monokai.codemirror.css
./src/themes/default/playground.css
./src/themes/default/print.js
./src/themes/default/screen.js
./src/utils/base.js
./src/utils/context.js
./src/utils/controller.js
./src/utils/playground.default-code.js
./src/utils/preloader.js
./src/utils/slides.js

/cc @kenwheeler