Bump version to v1.3.1

Change-Id: Ib09fb39e241d670a1ed98f585c4055c550f7fc15
diff --git a/CMakeLists.txt b/CMakeLists.txt
index adc8496..6a9ec62 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.9)
-project(collocatordb VERSION 1.3.0 DESCRIPTION "Storing and retrieving collocation counts based on RocksDB")
+project(collocatordb VERSION 1.3.1 DESCRIPTION "Storing and retrieving collocation counts based on RocksDB")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -fno-rtti -std=c++11 -std=gnu++11")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g")
 
diff --git a/README.md b/README.md
index b7eb570..360acec 100644
--- a/README.md
+++ b/README.md
@@ -97,6 +97,11 @@
 void read_vocab(COLLOCATORDB *db, char *fname);
 ```
 
+## Changes
+
+* v1.3.1 (2024-11-14)
+  * fixed calculation of total token count
+
 ## TODO
 
 * extend API