Only build universal binary if universal2 Python is available

Closes #576

bundledApps/MAKEFILE.sh

@@ -86,7 +86,16 @@ createBinary ()
 {
   echo "Creating binary"
   which pyinstaller
-  pyinstaller -p bundledApps ./bundledApps/WAIL.py --onefile --windowed --clean --target-arch universal2 --icon="./build/icons/wail_blue.icns"
+
+  # Only specify the universal2 flag if an appropriate Python is installed, otherwise use default
+  if file `which python3` | grep 'universal'; then
+    echo "🌌 Building universal binary"
+    archflag=(--target-arch universal2)
+  else
+    echo "🍎 Building native single-architecture binary"
+  fi
+
+  pyinstaller -p bundledApps ./bundledApps/WAIL.py --onefile --windowed --clean "${archflag[@]}" --icon="./build/icons/wail_blue.icns"
   # Replace default version and icon information from pyinstaller 
   cp ./build/Info.plist ./dist/WAIL.app/Contents/Info.plist
   # Copy the bundledApps and support directories to inside WAIL.app/