delete the Dockerfile-55 file and rename Dockerfile-56 to Dockerfile-5

Since 5.5 and 5.6 dockerfiles are identical execept the base image php version.
Will let the users switch the php 5.6 and 5.5 version from the Dockerfile-5 by changing one char
in the first line. Removing this duplication will make contribution and maintance easier and faster.

php-fpm/Dockerfile-55

@@ -1,52 +0,0 @@
-FROM php:5.5-fpm
-
-MAINTAINER Mahmoud Zalt <mahmoud@zalt.me>
-
-ADD ./laravel.ini /usr/local/etc/php/conf.d
-ADD ./laravel.pool.conf /usr/local/etc/php-fpm.d/
-
-RUN apt-get update && apt-get install -y \
-    libpq-dev \
-    libmemcached-dev \
-    curl \
-    libjpeg-dev \
-    libpng12-dev \
-    libfreetype6-dev \
-    libssl-dev \
-    libmcrypt-dev \
-    --no-install-recommends \
-    && rm -r /var/lib/apt/lists/*
-
-# install mcrypt library
-RUN docker-php-ext-install mcrypt
-
-# Install mongodb driver
-RUN pecl install mongodb
-
-# configure gd library
-RUN docker-php-ext-configure gd \
-    --enable-gd-native-ttf \
-    --with-jpeg-dir=/usr/lib \
-    --with-freetype-dir=/usr/include/freetype2
-
-# Install extensions using the helper script provided by the base image
-RUN docker-php-ext-install \
-    pdo_mysql \
-    pdo_pgsql \
-    gd
-
-# Install memcached
-RUN pecl install memcached \
-    && docker-php-ext-enable memcached
-
-# Install xdebug
-RUN pecl install xdebug \
-    && docker-php-ext-enable xdebug
-
-RUN usermod -u 1000 www-data
-
-WORKDIR /var/www/laravel
-
-CMD ["php-fpm"]
-
-EXPOSE 9000