Swift 2.3 compatibility update

CryptoSwift.xcodeproj/project.pbxproj

@@ -759,9 +759,11 @@
 					};
 					754BE45419693E190098E6F3 = {
 						CreatedOnToolsVersion = 6.0;
+						LastSwiftMigration = 0800;
 					};
 					754BE45F19693E190098E6F3 = {
 						CreatedOnToolsVersion = 6.0;
+						LastSwiftMigration = 0800;
 						TestTargetID = 754BE45419693E190098E6F3;
 					};
 				};
@@ -1288,6 +1290,7 @@
 				PRODUCT_NAME = CryptoSwift;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 2.3;
 			};
 			name = Debug;
 		};
@@ -1313,6 +1316,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_DISABLE_SAFETY_CHECKS = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
+				SWIFT_VERSION = 2.3;
 			};
 			name = Release;
 		};
@@ -1335,6 +1339,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.hakore.${PRODUCT_NAME:rfc1034identifier}";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = CryptoSwiftTests/Bridging.h;
+				SWIFT_VERSION = 2.3;
 			};
 			name = Debug;
 		};
@@ -1357,6 +1362,7 @@
 				SWIFT_DISABLE_SAFETY_CHECKS = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = CryptoSwiftTests/Bridging.h;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
+				SWIFT_VERSION = 2.3;
 			};
 			name = Release;
 		};