Bumping versions for version update (0.1.8). (#187)

- iOS:
-- TabBarView: snap tab bar height to 4pt grid (48pt on iPad and iPhone - all orientations)
-- TabBarItem: added support for badges, customizable accessibility labels
-- DateTimePicker: updated past days text color to textPrimary (light mode) and textSecondary (dark mode), conforms backgrounds of the heading and the the navigation bar
-- AvatarGroupView: new component to display avatar view grouped as a pile (side by side) or as a stack (overlapping)
-- AvatarView: added support for displaying a avatar border in a specific color
-- TableViewCellFileAccessoryView: added large content interaction support for accessory view items, changed objC name from TableViewCellFileAccessoryView to MSFTableViewCellFileAccessoryView, exposed initializer to objC