Fix images in GitHub READMEs.

* Use raw. URLs instead of /blob
* Fix img src as well, not just a href
Merge pull request #123 from neonichu/fix-readme-imgs

Fix images in GitHub READMEs.
Make sure https links are getting mangled.
Use https for GH links.
Merge pull request #124 from neonichu/fix-readme-imgs

Fix readme imgs
add support for generating latest podspec
actually make days work again