travis: change matrix and add fast finish

Travis has fixed the bug affecting cache's names so we don't need custom compiler names anymore
Change and reorder jobs
Also add fast finish, so that when a job fails, the build fails immediately

.travis.yml

@@ -55,25 +55,23 @@ notifications:
     on_failure: always  # options: [always|never|change] default: always
     on_start: false     # default: false
 
+compiler:
+  - gcc
+  - clang
+
 env:
   global:
     # The next declaration is the encrypted COVERITY_SCAN_TOKEN, created
     #   via the "travis encrypt" command using the project repo's public key
     - secure: "FjIwqZQV2FhNPWYITX5LZXTE38yYqBaQdbm3QmbEg/30wnPTm1ZOLIU7o/aSvX615ImR8kHoryvFPDQDWc6wWfqTEs3Ytq2kIvcIJS2Y5l/0PFfpWJoH5gRd6hDThnoi+1oVMLvj1+bhn4yFlCCQ2vT/jxoGfiQqqgvHtv4fLzI="
-
-# Note: while https://github.com/travis-ci/travis-ci/issues/4393 isn't solved we need to hack compiler name to have cache work properly
+  matrix:
+    - CI_BUILD_TARGET="sitl minlure raspilot"
+    - CI_BUILD_TARGET="linux navio2 bebop"
 
 matrix:
+  fast_finish: true
   include:
-    - compiler: "gcc PX4"
+    - compiler: "gcc"
       env: CI_BUILD_TARGET="px4-v2 px4-v4"
-    - compiler: "gcc Native"
-      env: CI_BUILD_TARGET="sitl linux minlure"
-    - compiler: "gcc Linux"
-      env: CI_BUILD_TARGET="navio2 raspilot bebop"
-    - compiler: "gcc SITL Test"
+    - compiler: "gcc"
       env: CI_BUILD_TARGET="sitltest"
-    - compiler: "clang Native"
-      env: CI_BUILD_TARGET="sitl linux minlure"
-    - compiler: "clang Linux"
-      env: CI_BUILD_TARGET="navio2 raspilot bebop"