TravisCI: remove allow_failures for thumb* targets

.travis.yml

@@ -28,11 +28,6 @@ matrix:
     - env: TARGET=x86_64-apple-darwin
       os: osx
     - env: TARGET=x86_64-unknown-linux-gnu
-  allow_failures:
-    - env: TARGET=thumbv6m-linux-eabi
-    - env: TARGET=thumbv7em-linux-eabi
-    - env: TARGET=thumbv7em-linux-eabihf
-    - env: TARGET=thumbv7m-linux-eabi
 
 install:
   - case $TARGET in