Project does not compile with current esp-idf master
Hi,

I'm trying to build the project with the current esp-idf master https://github.com/espressif/esp-idf/commit/58df1d93bc17c74499d58e05390af9c309192a5c

The build fails with the follwing error

```
In file included from .../Homepoint/components/arduino-esp32/cores/esp32/wiring_private.h:31,
                 from .../Homepoint/components/arduino-esp32/cores/esp32/wiring_pulse.c:18:
.../Homepoint/components/arduino-esp32/cores/esp32/Arduino.h:121:6: error: conflicting types for 'random'
 long random(long, long);
      ^~~~~~
In file included from .../Homepoint/components/arduino-esp32/cores/esp32/Arduino.h:28,
                 from .../Homepoint/components/arduino-esp32/cores/esp32/wiring_private.h:31,
                 from .../Homepoint/components/arduino-esp32/cores/esp32/wiring_pulse.c:18:
.../xtensa-esp32-elf-8.2.0/xtensa-esp32-elf/sys-include/stdlib.h:267:6: note: previous declaration of 'random' was here
 long random (void);
      ^~~~~~
```

I know it's the (unstable) compiler version 8.2.0. when I use the compiler version 5.2.0 cmake will refuse to build.

I think it's a temporary problem since I already build Homepoint successfully.

I wonder if it's good to relate on the master branch of ESP-IDF. It seems to be pretty unstable. Unfortunatly earlier versions won't support cmake very well.
