Merge branch 'rpi' of https://github.com/adrianiainlam/mouse-tracker-for-cubism into rpi

The CMake min version change was somehow missing in my local tree

diff --cc example/demo.patch
index e7d5114,a083a76..10395d7
--- 1/example/demo.patch
--- 2/example/demo.patch
+++ b/example/demo.patch
@@@ -1,7 -1,10 +1,10 @@@
  diff -pruN --exclude build ./demo_clean/CMakeLists.txt ./demo_dev/CMakeLists.txt
 ---- ./demo_clean/CMakeLists.txt       2021-01-13 16:58:08.359828681 +0000
 -+++ ./demo_dev/CMakeLists.txt 2021-01-13 17:22:01.166356692 +0000
 +--- ./demo_clean/CMakeLists.txt       2021-02-17 01:23:17.000000000 +0000
 ++++ ./demo_dev/CMakeLists.txt 2021-04-28 12:32:48.468744883 +0100
- @@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.16)
+ @@ -1,9 +1,9 @@
+ -cmake_minimum_required(VERSION 3.16)
+ +cmake_minimum_required(VERSION 3.13)
+  
   # Set app name.
   set(APP_NAME Demo)
   # Set directory paths.