libretro: Add Travis testing (#62)

* libretro: Add Travis testing

* libretro: Remove Travis testing other platforms

.travis.yml

-language: cpp
-matrix:
-  include:
-    - os: linux
-      env: NAME="clang-format"
-      dist: trusty
-      addons:
-        apt:
-          sources:
-            - llvm-toolchain-trusty-6.0
-            - ubuntu-toolchain-r-test
-          packages:
-            - clang-format-6.0
-      script: "./.travis/clang-format/script.sh"
-    - os: linux
-      env: NAME="linux build"
-      sudo: required
-      dist: trusty
-      services: docker
-      addons:
-        apt:
-          packages:
-            - p7zip-full
-      install: "./.travis/linux/deps.sh"
-      script: "./.travis/linux/build.sh"
-      after_success: "./.travis/linux/upload.sh"
-      cache: ccache
-    - if: repo = citra-emu/citra AND branch = master AND type = push
-      os: linux
-      env: NAME="transifex push"
-      sudo: required
-      dist: trusty
-      services: docker
-      install: "./.travis/transifex/deps.sh"
-      script: "./.travis/transifex/build.sh"
-    - os: osx
-      env: NAME="macos build"
-      sudo: false
-      osx_image: xcode10
-      install: "./.travis/macos/deps.sh"
-      script: "./.travis/macos/build.sh"
-      after_success: "./.travis/macos/upload.sh"
-      cache: ccache
-    - os: linux
-      env: NAME="linux build (frozen versions of dependencies)"
-      sudo: required
-      dist: trusty
-      services: docker
-      cache: ccache
-      script: "./.travis/linux-frozen/build.sh"
-    - os: linux
-      env: NAME="MinGW build"
-      sudo: required
-      dist: trusty
-      services: docker
-      addons:
-        apt:
-          packages:
-            - p7zip-full
-      install: "./.travis/linux-mingw/deps.sh"
-      script: "./.travis/linux-mingw/build.sh"
-      after_success: "./.travis/linux-mingw/upload.sh"
-      cache: ccache
-
-deploy:
-  provider: releases
-  api_key:
-    secure: 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
-  file_glob: true
-  file: "artifacts/*"
-  skip_cleanup: true
-  on:
-    tags: true
-
-notifications:
-  webhooks:
-    urls:
-      - https://api.citra-emu.org/code/travis/notify
+language: generic
+os: linux
+dist: trusty
+sudo: required
+addons:
+  apt:
+    packages:
+      - g++-7
+    sources:
+      - ubuntu-toolchain-r-test
+env:
+  global:
+    - CORE=citra
+    - COMPILER_NAME=gcc CXX=g++-7 CC=gcc-7
+  matrix:
+    - PLATFORM=linux_x64
+before_script:
+  - pwd
+  - mkdir -p ~/bin
+  - ln -s /usr/bin/gcc-7 ~/bin/gcc
+  - ln -s /usr/bin/g++-7 ~/bin/g++
+  - ln -s /usr/bin/cpp-7 ~/bin/cpp
+  - export PATH=~/bin:$PATH
+  - ls -l ~/bin
+  - echo $PATH
+  - g++-7 --version
+  - g++ --version
+script:
+  - cd ~/
+  - git clone --depth=50 https://github.com/libretro/libretro-super
+  - cd libretro-super/travis
+  - ./build.sh