Add images for PHP 7.4 and 8.0

php/7.4/Dockerfile

+FROM php:7.4-buster
+
+LABEL maintainer="ethitter"
+LABEL version="1.0"
+
+RUN apt-get update \
+    && apt-get -yqqf install lsb-release zip unzip rsync subversion git libicu-dev libpng-dev libbz2-dev default-libmysqlclient-dev libzip-dev libonig-dev --fix-missing --no-install-recommends \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN docker-php-ext-install mbstring mysqli intl gd zip bz2
+
+SHELL ["/bin/bash", "-o", "pipefail", "-c"]
+RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
+RUN chmod +x /usr/local/bin/composer
+
+ENV PATH=/root/.composer/vendor/bin:$HOME/.composer/vendor/bin:$PATH