install libtool-bin

.travis.yml

@@ -5,7 +5,7 @@ language: c
 
 before_install:
     - sudo apt-get update -qq
-    - sudo apt-get install -y clang libtommath-dev libgmp-dev libtfm-dev valgrind
+    - sudo apt-get install -y libtommath-dev libgmp-dev libtfm-dev valgrind libtool-bin
 
 before_script:
   - gem install coveralls-lcov