Put PHP extension installation into a shell script.

.travis.yml

@@ -14,8 +14,7 @@ env:
     - secure: "jtQTZKQBnzUlp/jz7NlM6470ZDnLGVAs53sgvIm4tcYqf9TWSXSXjIYvFsrS\nKPR2eyZaAevYysUkIGRFTUXTlG6tC36YngMp9+6FPxASl8mnGXsTbKcm613B\n59vD3242pgIgqhhmgFQ0c8gbvnE8PuF2aS4/hluP3r+AxhWN56E="
 
 before_script:
-  - git clone git://github.com/zenovich/runkit.git && cd runkit && phpize && ./configure && make && make install && cd ..
+  - travis/install-php-extensions.sh
-  - echo "extension=runkit.so" >> `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"`
   - sh -c "if [ '$TRAVIS_PHP_VERSION' = '5.5' ]; then composer install --dev --no-interaction; fi"
 
 script:

travis/install-php-extensions.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This file is part of the phpseclib project.
+#
+# (c) Andreas Fischer <bantu@phpbb.com>
+#
+# For the full copyright and license information, please view the LICENSE
+# file that was distributed with this source code.
+#
+set -e
+
+function install_php_extension
+{
+    cd "$1"
+    phpize
+    ./configure
+    make
+    make install
+    cd ..
+    echo "extension=$1.so" >> `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"`
+}
+
+# runkit
+git clone git://github.com/zenovich/runkit.git
+install_php_extension 'runkit'