Test v5 on PHP 7.3 (#1647)

* support for PHP 7.3

.travis.yml

@@ -18,6 +18,7 @@ env:
     - TARGET="70"
     - TARGET="71"
     - TARGET="72"
+    - TARGET="73"
 
 before_install:
   # check running "docker engine" and "docker-compose" version on travis

CHANGELOG.md

@@ -13,6 +13,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Improvements
 
 - Update `elasticsearch-php` dependency to 5.4 [#1648](https://github.com/ruflin/Elastica/pull/1648)
+- Add testing on PHP 7.3 on Travis [#1647](https://github.com/ruflin/Elastica/pull/1647)
 
 
 ## [5.3.5](https://github.com/ruflin/Elastica/compare/5.3.4...5.3.5)

env/elastica/Docker73

@@ -0,0 +1,36 @@
+# This image is the base image for the Elastica development and includes all parts which rarely change
+# PHP 7 Docker file with Composer installed
+FROM php:7.3
+MAINTAINER Nicolas Ruflin <[email protected]>
+
+RUN apt-get update && apt-get install -y \
+	cloc \
+	git \
+	graphviz \
+	libxslt-dev \
+	nano \
+	zip unzip \
+	wget
+	# XSL and Graphviz for PhpDocumentor
+
+RUN docker-php-ext-install sockets xsl
+
+RUN rm -r /var/lib/apt/lists/*
+
+## PHP Configuration
+RUN pecl install xdebug-2.7.2
+
+RUN echo "memory_limit=1024M" >> /usr/local/etc/php/conf.d/memory-limit.ini
+RUN echo "date.timezone=UTC" >> /usr/local/etc/php/conf.d/timezone.ini
+
+# Install and setup composer
+RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
+ENV COMPOSER_HOME /root/composer
+
+# Add composer bin to the environment
+ENV PATH=/root/composer/vendor/bin:$PATH
+
+COPY composer.json /root/composer/
+
+# Install development tools, prefer source removed as automatic fallback now
+RUN composer global install