[Example] Clean up pod and fix warning

Example/Podfile

@@ -1,5 +1,7 @@
 source 'https://github.com/CocoaPods/Specs.git'
 
+platform :ios, '9.3'
+
 # ignore all warnings from all pods
 inhibit_all_warnings!
 
@@ -27,4 +29,4 @@ post_install do |installer|
       config.build_settings['SWIFT_VERSION'] = '4.0'
     end
   end
-end
+end

Example/Podfile.lock

@@ -9,7 +9,7 @@ DEPENDENCIES:
   - SnapKit (~> 4.0.0)
 
 SPEC REPOS:
-  https://github.com/CocoaPods/Specs.git:
+  https://github.com/cocoapods/specs.git:
     - Nimble
     - Quick
     - SnapKit
@@ -19,6 +19,6 @@ SPEC CHECKSUMS:
   Quick: 2623cb30d7a7f41ca62f684f679586558f483d46
   SnapKit: 0de968a9fec17499afa29683b05d0c775b6d1c29
 
-PODFILE CHECKSUM: 14489d38b0980855eca2cc9f747e94c1b31ef727
+PODFILE CHECKSUM: 79cef7f3459434f125fc2a9afd460e53dad46f6a
 
-COCOAPODS: 1.5.0
+COCOAPODS: 1.5.3

Example/RPCircularProgressExample.xcodeproj/project.pbxproj

@@ -355,6 +355,7 @@
 		D427C2621CB47563004980FF /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = "$(inherited)";
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
@@ -412,6 +413,7 @@
 		D427C2631CB47563004980FF /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = "$(inherited)";
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
@@ -464,7 +466,7 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 3A61E12C8FDC9C33D8D03A41 /* Pods-RPCircularProgressExample.debug.xcconfig */;
 			buildSettings = {
-				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = "$(inherited)";
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CLANG_ENABLE_MODULES = YES;
 				DEVELOPMENT_TEAM = S4JEZRL8YY;
@@ -481,7 +483,7 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 3030D6731270A8713109E432 /* Pods-RPCircularProgressExample.release.xcconfig */;
 			buildSettings = {
-				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = "$(inherited)";
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CLANG_ENABLE_MODULES = YES;
 				DEVELOPMENT_TEAM = S4JEZRL8YY;
@@ -497,7 +499,7 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = D1DAF3A9CF184C74441E9502 /* Pods-RPCircularProgressTests.debug.xcconfig */;
 			buildSettings = {
-				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = "$(inherited)";
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				INFOPLIST_FILE = ../Tests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
@@ -512,7 +514,7 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 2902856555A2E0F3C5E94DC9 /* Pods-RPCircularProgressTests.release.xcconfig */;
 			buildSettings = {
-				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = "$(inherited)";
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				INFOPLIST_FILE = ../Tests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";

Source/RPCircularProgress.swift

@@ -222,7 +222,7 @@ open class RPCircularProgress: UIView {
             // Basic animations have their value reset to the original once the animation is finished
             // since only the presentation layer is animating
             var currentProgress: CGFloat = 0
-            if let presentationLayer = progressLayer.presentation() as? ProgressLayer {
+            if let presentationLayer = progressLayer.presentation() {
                 currentProgress = presentationLayer.progress
             }
             progressLayer.progress = currentProgress