Removed an unnecessary line of code

When we resignFirstResponder, UIKeyboardWillHideNotification is called. If someone does a custom thing when the keyboard becomes hidden it brings problems. When we remove this line, it won't do any harm.

What do you think?
Merge pull request #171 from tasomaniac/patch-1

Removed resignFirstResponder, as becomeFirstResponder is called right after it anyway.
Enabled iPhone 6 and iPhone 6 Plus screen sizes.
Fixed header and section issues on iOS 8 (due to header and footer height estimation used instead of recalculating the actual height).
Merge pull request #190 from max-horvath/ios8-fixes

Example app runs nicely on new iPhone devices, as well as some iOS 8 fixes.
Version bump (1.5.13)
Fix compile errors on Xcode 5.1 iOS SDK 7.1
Merge pull request #194 from guoxj/master

Fix compile errors on Xcode 5.1 iOS SDK 7.1
Version bump (1.5.14)
Merge branch 'master' of https://github.com/romaonthego/RETableViewManager