No error if clippy install fails

.travis.yml

@@ -13,9 +13,5 @@ matrix:
   include:
     - rust: nightly
       env: CLIPPY=true
-  allow_failures:
-    - rust: nightly
-      env: CLIPPY=true
-  fast_finish: true
 
 script: ./travis.sh

travis.sh

@@ -17,9 +17,10 @@ channel() {
 }
 
 if [ -n "${CLIPPY}" ]; then
-    if [ -n "${TRAVIS}" ]; then
     # cached installation will not work on a later nightly
-        cargo install clippy --debug --force
+    if [ -n "${TRAVIS}" ] && ! cargo install clippy --debug --force; then
+        echo "COULD NOT COMPILE CLIPPY, IGNORING CLIPPY TESTS"
+        exit
     fi
 
     cd "$DIR/serde"