feat: install PHP intl extension

The extension is required by the SDK generator. Without it, the SDK generator
would throw an error like:

    Class Normalizer not found

Author: stnguyen90

Dockerfile

@@ -191,7 +191,7 @@ RUN \
   docker-cli \
   libgomp \
   git \
-  && docker-php-ext-install sockets pdo_mysql pdo_pgsql \
+  && docker-php-ext-install sockets pdo_mysql pdo_pgsql intl \
   && apk del .deps \
   && rm -rf /var/cache/apk/*
 

tests.yaml

@@ -134,3 +134,8 @@ commandTests:
       - ".*brotli.*"
       - ".*lz4.*"
       - ".*snappy.*"
+  - name: 'PHP intl'
+    command: "php"
+    args: ["-r", 'print(\Normalizer::FORM_D);']
+    expectedOutput:
+      - "4"