Violates the new github CSP header

[MassiveHiggsField]

The content security policy of github doesn't allow this extension to work. Error is:

Refused to load the script 'https://platform.harvestapp.com/assets/platform.js' because it violates the following Content Security Policy directive: "script-src 'self' https://github.global.ssl.fastly.net https://jobs.github.com https://ssl.google-analytics.com https://collector.githubapp.com https://analytics.githubapp.com".

I think there are to possible fixes:

1. Integrate the platform.js in the extension
2. Try to bypass the csp header

[calmyournerves]

Fixed this here (method 2): https://github.com/calmyournerves/github-time-tracking/commit/ea795b031e0201e9ce2bcbb404b881a36befa722

Will test it again and create a PR when I get to it.

[calmyournerves]

Done, see https://github.com/klokantech/github-time-tracking/pull/6

[klokan]

Thank you. Deployed.