Fix esp-idf dependencies (closes #161)

Author: mathieucarbou

idf_component.yml

@@ -25,6 +25,9 @@ files:
     - "platformio.ini"
     - "pre-commit.requirements.txt"
 dependencies:
+  espressif/arduino-esp32:
+    version: "^3.1.1"
+    require: public
   esp32async/asynctcp:
     version: "^3.4.0"
     require: public