Removed reference to Swift Package Manager.

Problem is that OCMock can't really work with SPM. See #500 for details.

index.html

@@ -29,7 +29,7 @@ <h2>Adding OCMock to your project</h2>
 	<li>Download a release from the <a href="{{ site.baseurl }}/download">downloads page</a>.
 	<li>For iOS development add the static library</a> to your test target. This is described in detail on the <a href="{{ site.baseurl }}/ios">iOS page</a>.
 	<li>For OS X development simply add <code>OCMock.framework</code> to your test target.
-	<li>Alternatively you can use  Carthage, CocoaPods, and Swift Package Manager.
+	<li>Alternatively you can use  Carthage or CocoaPods.
 	<li>Add an import to your unit tests.
 </ul>
 {% highlight objc %}