Install php-redis dependencies in Dockerfile

images/Dockerfile

@@ -54,7 +54,12 @@ RUN set -eux; \
 		mysql-client \
 	; \
     \
-    rm -rf /tmp/pear \
+    # install redis
+	pecl install -o -f redis \
+	; \
+	rm -rf /tmp/pear \
+	; \
+	docker-php-ext-enable redis \
     ; \
 	\
 	docker-php-ext-configure gd \