Merge pull request 'Add intl extension to dockerfile' (#6) from fix/missing-intl-extension into master

Reviewed-on: #6

Dockerfile

@@ -5,9 +5,10 @@ WORKDIR /usr/src/app
 RUN apt-get update && apt-get install -y \
     git \
     unzip \
+    libicu-dev \
     libzip-dev
 
-RUN docker-php-ext-install zip
+RUN docker-php-ext-install zip intl
 
 RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer