Perform xcode project upgrade

This includes changing compatibility with xcode from 9.3 to 10.0, though it shouldn't have notable impact since the oldest Swift version that we support comes from xcode 10.

SWCompression.xcodeproj/xcshareddata/xcschemes/SWCompression.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0930"
+   LastUpgradeVersion = "1240"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -27,6 +27,15 @@
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "06BE1AC71DB410F100EE0F59"
+            BuildableName = "SWCompression.framework"
+            BlueprintName = "SWCompression"
+            ReferencedContainer = "container:SWCompression.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <Testables>
          <TestableReference
             skipped = "NO"
@@ -41,17 +50,6 @@
             </BuildableReference>
          </TestableReference>
       </Testables>
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "06BE1AC71DB410F100EE0F59"
-            BuildableName = "SWCompression.framework"
-            BlueprintName = "SWCompression"
-            ReferencedContainer = "container:SWCompression.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"
@@ -72,8 +70,6 @@
             ReferencedContainer = "container:SWCompression.xcodeproj">
          </BuildableReference>
       </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"