Updating .swift-version to swift 5.0

Bumping pod spec version to 2.6.4

Bumping podspec for release 2.6.3

Bumping podspec version for release

Updating var to let for safeAreaTopInset and safeAreaBottomInset in h…

…eightOfOpenDrawer

Updating .swift_version for 4.2 release

Update readme, fix merge issue, bump pod version for 2.5.0 release.

Bump podspec