Allow failures for currently failing targets

Author: Susurrus

.travis.yml

@@ -77,6 +77,12 @@ matrix:
     - env: TARGET=x86_64-apple-darwin
       os: osx
       rust: nightly
+    # FIXME: targets that should pass but are currently failing
+    - env: TARGET=i686-unknown-linux-musl
+    - env: TARGET=x86_64-unknown-linux-musl
+    - env: TARGET=mips-unknown-linux-gnu
+    - env: TARGET=mipsel-unknown-linux-gnu
+    - env: TARGET=powerpc-unknown-linux-gnu
 
 install:
   - sh ci/install.sh