remove travis CI configuration

.travis.yml

@@ -1,19 +0,0 @@
-language: c
-sudo: true
-dist: bionic
-
-before_install:
-  - wget "https://github.com/devkitPro/pacman/releases/latest/download/devkitpro-pacman.amd64.deb" -O dkp-pacman.deb
-  - export DEVKITPRO=/opt/devkitpro
-  - export DEVKITARM=${DEVKITPRO}/devkitARM
-
-install:
-  - sudo apt-get -y install python3 python3-pip p7zip-full libarchive13
-  - sudo dpkg -i dkp-pacman.deb
-  - sudo dkp-pacman -S --noconfirm devkitARM
-  - sudo pip3 install --upgrade pip setuptools
-  - sudo pip3 install cryptography
-  - sudo pip3 install git+https://github.com/TuxSH/firmtool.git
-
-script:
-  - make release