Fixed @gali8's README change re: tesseract version

@gali8, the version of THIS REPOSITORY and the framework it provides is 3.1.1. But the version of the UPSTREAM Tesseract library (libtesseract_all.a) included is 3.03. Therefore, the line I've reverted from your recent commit needs to say 3.03, not 3.1.1, because it's describing the version of the upstream .a library file, not the version of this repository. I've added some clarification around this part of the README, including links to the upstream library homepages. I've also removed the CocoaPods badge since it was not updating to show that 3.1.1 is the latest CocoaPods release, and therefore it might have been causing your confusion. My guess is that either Cocoa Pods thinks that 3.03 is a newer version number than 3.1.1, or GitHub is heavily caching the badge image since the badge was rendered before we pushed release 3.1.1 to CocoaPods.