Adding SOVERSION property to shared library (#262)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e4aa83f..7291e78 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,7 +83,9 @@
 )
 set_target_properties(
     qcbor PROPERTIES
-    PUBLIC_HEADER "${HEADERS}"
+        VERSION ${PROJECT_VERSION}
+        SOVERSION ${PROJECT_VERSION_MAJOR}
+        PUBLIC_HEADER "${HEADERS}"
 )
 include(GNUInstallDirs)
 install(