Update README URLs based on HTTP redirects

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Created with https://github.com/dkhamsing/frankenstein

GitHub Corrected URLs

Was	Now
https://github.com/airportyh/testem	https://github.com/testem/testem

HTTPS Corrected URLs

Was	Now
http://github.com/power-assert-js/empower	https://github.com/power-assert-js/empower
http://github.com/power-assert-js/espower	https://github.com/power-assert-js/espower
http://github.com/power-assert-js/espower-cli	https://github.com/power-assert-js/espower-cli
http://github.com/power-assert-js/espower-coffee	https://github.com/power-assert-js/espower-coffee
http://github.com/power-assert-js/espower-loader	https://github.com/power-assert-js/espower-loader
http://github.com/power-assert-js/espower-source	https://github.com/power-assert-js/espower-source
http://github.com/power-assert-js/espower-typescript	https://github.com/power-assert-js/espower-typescript
http://github.com/power-assert-js/espowerify	https://github.com/power-assert-js/espowerify
http://github.com/power-assert-js/grunt-espower	https://github.com/power-assert-js/grunt-espower
http://github.com/power-assert-js/gulp-espower	https://github.com/power-assert-js/gulp-espower
http://github.com/power-assert-js/power-assert	https://github.com/power-assert-js/power-assert
http://github.com/power-assert-js/power-assert-formatter	https://github.com/power-assert-js/power-assert-formatter
http://github.com/twada	https://github.com/twada
http://github.com/twada/power-assert-demo	https://github.com/twada/power-assert-demo
http://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat	https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat
http://nodejs.org/api/assert.html	https://nodejs.org/api/assert.html
http://travis-ci.org/power-assert-js/power-assert	https://travis-ci.org/power-assert-js/power-assert

Other Corrected URLs

Was	Now
https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API	https://developer.mozilla.org/en-US/docs/Mozilla/Projects/SpiderMonkey/Parser_API
https://npmjs.org/package/power-assert	https://www.npmjs.com/package/power-assert

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