Remove disused PHP 5.3 image

php/5.3/Dockerfile

-FROM tetraweb/php:5.3
-
-LABEL maintainer="ethitter"
-LABEL version="1.0"
-
-RUN apt-get update \
-    && apt-get -yqqf install lsb-release zip unzip rsync subversion git mysql-client libicu-dev libpng-dev libbz2-dev libmysqlclient-dev libfreetype6-dev libjpeg-dev libxpm-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