Delete .travis.yml

.travis.yml

@@ -1,22 +0,0 @@
-# Enable validating this file
-version: ~> 1.0
-
-language: python
-python:
-    - "3.9"
-sudo: false
-cache:
-    directories:
-        - "~/.platformio"
-
-jobs:
-  include:
-    - install:
-      - pip install -U platformio
-      - platformio update
-      script: ./build_platformio.sh
-
-notifications:
-  email:
-    on_success: change
-    on_failure: change