Update podspec for Swift 4 support

Author: iwb-kevin-hirsch

.swift-version

@@ -1 +1 @@
-3.0
+4.0

DropDown.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name = "DropDown"
-  s.version = "2"
+  s.version = "2.0.1"
   s.summary = "A Material Design drop down"
 
   s.description = <<-DESC

DropDown.xcodeproj/project.pbxproj

@@ -290,11 +290,11 @@
 				TargetAttributes = {
 					0A76440E1B676C2300BF1A2D = {
 						CreatedOnToolsVersion = 6.4;
-						LastSwiftMigration = 0800;
+						LastSwiftMigration = 0910;
 					};
 					0A7644231B676C2300BF1A2D = {
 						CreatedOnToolsVersion = 6.4;
-						LastSwiftMigration = 0800;
+						LastSwiftMigration = 0910;
 						TestTargetID = 0A76440E1B676C2300BF1A2D;
 					};
 					0AB5D8701D0EEECD002D3A17 = {
@@ -461,7 +461,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -507,7 +507,7 @@
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				VALIDATE_PRODUCT = YES;
 			};
 			name = Release;
@@ -524,6 +524,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.assistoLab.Demo;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -539,6 +540,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.assistoLab.Demo;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
@@ -555,6 +557,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.kevin.hirsch.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Demo.app/Demo";
 			};
 			name = Debug;
@@ -567,6 +570,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.kevin.hirsch.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Demo.app/Demo";
 			};
 			name = Release;
@@ -591,7 +595,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -616,7 +619,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";