Revert "moved Material 3 to iOS 10+"

This reverts commit c8d3d142.

Material.xcodeproj/project.pbxproj

@@ -1253,7 +1253,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				MACOSX_DEPLOYMENT_TARGET = 10.9;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -1307,7 +1307,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				MACOSX_DEPLOYMENT_TARGET = 10.9;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				PRODUCT_NAME = Material;

Sources/Frameworks/Motion/Sources/Animator/MotionViewPropertyViewContext.swift

@@ -28,6 +28,7 @@
 
 import UIKit
 
+@available(iOS 10, tvOS 10, *)
 internal class MotionViewPropertyViewContext: MotionAnimatorViewContext {
     /// A reference to the UIViewPropertyAnimator.
     fileprivate var viewPropertyAnimator: UIViewPropertyAnimator?

Sources/Frameworks/Motion/Sources/Extensions/Motion+CALayer.swift

@@ -25,6 +25,7 @@
 
 import UIKit
 
+@available(iOS 10, *)
 extension CALayer: CAAnimationDelegate {}
 
 internal extension CALayer {

Sources/Frameworks/Motion/Sources/MotionAnimation.swift

@@ -370,6 +370,7 @@ public extension MotionAnimation {
      - Parameter damping: A CGFloat.
      - Returns: A MotionAnimation.
      */
+    @available(iOS 9, *)
     static func spring(stiffness: CGFloat, damping: CGFloat) -> MotionAnimation {
         return MotionAnimation {
             $0.spring = (stiffness, damping)

Sources/Frameworks/Motion/Sources/MotionCAAnimation.swift

@@ -81,6 +81,7 @@ fileprivate extension MotionCAAnimation {
     }
 }
 
+@available(iOS 9.0, *)
 internal extension MotionCAAnimation {
     /**
      Converts a CABasicAnimation to a CASpringAnimation.

Sources/Frameworks/Motion/Sources/MotionController.swift

@@ -500,7 +500,10 @@ fileprivate extension MotionController {
     /// Prepares the animators.
     func prepareAnimators() {
         animators.append(MotionTransitionAnimator<MotionCoreAnimationViewContext>())
-        animators.append(MotionTransitionAnimator<MotionViewPropertyViewContext>())
+        
+        if #available(iOS 10, tvOS 10, *) {
+            animators.append(MotionTransitionAnimator<MotionViewPropertyViewContext>())
+        }
         
         for v in animators {
             v.context = context

Sources/Frameworks/Motion/Sources/MotionTransition.swift

@@ -421,6 +421,7 @@ public extension MotionTransition {
      - Parameter damping: A CGFloat.
      - Returns: A MotionTransition.
      */
+    @available(iOS 9, *)
     static func spring(stiffness: CGFloat, damping: CGFloat) -> MotionTransition {
         return MotionTransition {
             $0.spring = (stiffness, damping)