Update php unit to Ubuntu 20.04 (#5713)

Also update php to v7.4

frameworks/PHP/php/README.md

@@ -10,18 +10,18 @@ The tests were run with [PHP Version 7.3.*](https://www.php.net/) + OPcache
 
 ### Platforms
 
-* [php-fpm 7.3.*](https://www.php.net/manual/en/install.fpm.php)
-* [nginx unit 1.11.0](https://unit.nginx.org/) (PHP 7.0)
+* [php-fpm 7.4.*](https://www.php.net/manual/en/install.fpm.php)
+* [nginx unit 1.18.0](https://unit.nginx.org/) (PHP 7.4)
 
 ### Webservers
 
-* [nginx 1.15.9](https://nginx.org/)
+* [nginx 1.17.10](https://nginx.org/)
 * [h2o 2.2.6](https://h2o.examp1e.net/)
 
 ### Databases
 
 * [MySQL 8](https://dev.mysql.com/)
-* [PostgreSQL 11](https://www.postgresql.org/)
+* [PostgreSQL 12](https://www.postgresql.org/)
 
 ## ActiveRecord
 

frameworks/PHP/php/php-unit.dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:19.10
+FROM ubuntu:20.04
 
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -8,7 +8,7 @@ RUN apt-get update -yqq > /dev/null && \
     apt-get install -yqq curl php-mysql > /dev/null
 
 RUN curl https://nginx.org/keys/nginx_signing.key | apt-key add - \
-    && add-apt-repository "deb https://packages.nginx.org/unit/ubuntu/ eoan unit" -s \
+    && add-apt-repository "deb https://packages.nginx.org/unit/ubuntu/ focal unit" -s \
     && apt-get -y update \
     && apt-get -y install unit unit-php