1. by bumping version of dependend jsdom to 0.2.19 fixed problems with using juice with node 9.3 (used node-gyp instead node-waf)
2. fixed problems with inproper construction of test/cases - in .html/.out files was invalid html documents, jsdom automaticly fix them by wrapping using <html><body></body></html> tags, so all test/cases/* were wrong
3. added new test/cases/empty* test to ensure that juice is shy and tidy and conserve unstyled tags and empty documents.
added test/cases/empty*
Merge branch 'master' of github.com:eoln/juice

Conflicts:
	test/cases/cascading.out
	test/cases/class+id.out
	test/cases/class.out
	test/cases/css-quotes.out
	test/cases/direct-descendents.out
	test/cases/id.out
	test/cases/ignore-pseudos.out
	test/cases/important.out
	test/cases/preserve-events.out
	test/cases/regression-selector-newline.out
	test/cases/specificity.out
	test/cases/style-preservation.out
	test/cases/tag.out
ability to type "npm test" to run tests