Install Intl extension on MAMP Pro for Mac

1. download icu http://site.icu-project.org/download
2. tar xzvf icu4c-54m1-src.tgz
3. cd icu/source
4. ./runConfigureICU MacOSX
5. ./configure
6. make
7. sudo make install

waiting for install icu completed.

8.  export PATH=/Applications/MAMP/bin/php/php5.5.3/bin:$PATH

9.  sudo pecl install intl

10. add "extension=intl.so" to php.ini

restart Apache.