Clean up after OCI8 install

Author: andrewnicols

root/tmp/setup/oci8-extension.sh

@@ -23,3 +23,6 @@ ln -s /usr/local/instantclient/sqlplus /usr/bin/sqlplus
 
 echo 'instantclient,/usr/local/instantclient' | pecl install oci8 && docker-php-ext-enable oci8
 echo 'oci8.statement_cache_size = 0' >> /usr/local/etc/php/conf.d/docker-php-ext-oci8.ini
+
+# Keep our image size down.
+pecl clear-cache