THRIFT-5621: Add Swift tutorial

Client: swift
diff --git a/configure.ac b/configure.ac
index 88271e6..a926e3e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -839,6 +839,7 @@
   tutorial/py.tornado/Makefile
   tutorial/rb/Makefile
   tutorial/rs/Makefile
+  tutorial/swift/Makefile
 ])
 
 if test "$have_cpp" = "yes" ; then MAYBE_CPP="cpp" ; else MAYBE_CPP="" ; fi