Merge pull request moodlehq#68 from stronk7/7.1-stretch

Let's remain sticky to Redis 4.3.0 (php71)

Author: andrewnicols

root/tmp/setup/php-extensions.sh

@@ -59,7 +59,7 @@ docker-php-ext-configure ldap --with-libdir=lib/x86_64-linux-gnu/
 docker-php-ext-install -j$(nproc) ldap
 
 # SOLR, Memcached, Redis, APCu, igbinary.
-pecl install solr memcached mongodb redis apcu igbinary
+pecl install solr memcached mongodb redis-4.3.0 apcu igbinary
 docker-php-ext-enable solr memcached mongodb redis apcu igbinary
 
 echo 'apc.enable_cli = On' >> /usr/local/etc/php/conf.d/docker-php-ext-apcu.ini