Added versioning borrowed fron GNU Radio to gr-gsm
diff --git a/swig/CMakeLists.txt b/swig/CMakeLists.txt
index 1c237c8..4766220 100644
--- a/swig/CMakeLists.txt
+++ b/swig/CMakeLists.txt
@@ -59,6 +59,7 @@
 install(
     FILES
     grgsm_swig.i
+    constants.i
     ${CMAKE_CURRENT_BINARY_DIR}/grgsm_swig_doc.i
     DESTINATION ${GR_INCLUDE_DIR}/grgsm/swig
 )