fix: height animation with keepViewsMounted

test: fix fillParent test

feat: add TS type defs

feat: add onSlideTransitionEnd prop, fix keepPrecedingViewsMounted

feat(SimpleViewSlider): add keepPrecedingViewsMounted prop

fix: flow errors

fix: move react-transition-context to dependencies

Merge pull request #5 from jcoreio/inner-view-wrapper-style

feat: add innerViewWrapperStyle prop

feat: add viewStyle prop

feat: add spacing and rtl props