Resolve "add simple unit tests for containers"

Closes #10 (closed)

php-unit-test/7.2/Dockerfile

@@ -14,7 +14,7 @@ LABEL org.label-schema.build-date=$BUILD_DATE \
 
 RUN apk add --no-cache bash nodejs nodejs-npm $PHPIZE_DEPS \
     && pecl install xdebug redis \
-    && docker-php-ext-enable xdebug redis
+    && docker-php-ext-enable xdebug redis \
     && apk del --no-cache $PHPIZE_DEPS
 RUN curl -o /usr/local/bin/composer https://getcomposer.org/composer.phar \
   && chmod 755 /usr/local/bin/composer