Fix CMake tarball used by travis

.travis.yml

@@ -10,7 +10,7 @@ before_install:
   - wget http://www.cmake.org/files/v3.7/cmake-3.7.2-Linux-x86_64.tar.gz
 install: 
   - tar -xf cmake-3.7.2-Linux-x86_64.tar.gz
-  - export PATH="${PWD}/cmake-3.7.1-Linux-x86_64/bin:${PATH}"
+  - export PATH="${PWD}/cmake-3.7.2-Linux-x86_64/bin:${PATH}"
   - pip install --user flake8
   - git config --global clangformat.binary clang-format-3.8
 env: