Talking about ARDUINO_IDE_VERSION (espressif#47)

* Note about installing multiple libraries

* "Hack" on how to install external libraries

* Explaining what ARDUINO_IDE_VERSION="1.8.7" does

The script usually chooses the newset stable version

* typo

Author: Leonardo

README.md

@@ -32,7 +32,8 @@ git:
   quiet: true
 env:
   global:
-     - ARDUINO_IDE_VERSION="1.8.7"
+     # You can uncomment this to explicitly choose an (old) version of the Arduino IDE
+     #- ARDUINO_IDE_VERSION="1.8.7"
 before_install:
   - source <(curl -SLs https://raw.githubusercontent.com/adafruit/travis-ci-arduino/master/install.sh)
 install: