Reverted swift tools version to 4.0 for backwards compatibility

stephencelis · sburlewapg · web-flow · commit e8ca9c0d138d · 2019-04-22T12:29:15.000-06:00
Co-Authored-By: sburlewapg &lt;49003548+sburlewapg@users.noreply.github.com&gt;
diff --git a/Package.swift b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.0
+// swift-tools-version:4.0
 import PackageDescription
 
 let package = Package(
