fix(ci): call cmake under /usr/local with sudo by passing $PATH environment variable

Author: Prcuvu

travis-before-install.sh

@@ -5,7 +5,7 @@ if [[ "$TRAVIS_OS_NAME" == linux ]]; then
   sudo apt-get install doxygen libboost-filesystem-dev libboost-locale-dev libboost-regex-dev libboost-signals-dev libboost-system-dev libgoogle-glog-dev libleveldb-dev libmarisa-dev libyaml-cpp-dev -y
   make thirdparty/gtest
   make -C thirdparty/src/opencc build
-  sudo make -C thirdparty/src/opencc install
+  sudo env "PATH=$PATH" make -C thirdparty/src/opencc install
 elif [[ "$TRAVIS_OS_NAME" == osx ]]; then
   make -f Makefile.xcode thirdparty
 fi