Add php mongodb driver. (#60)

diff --git a/core/php7.3Action/CHANGELOG.md b/core/php7.3Action/CHANGELOG.md
index bef4c7e..c223ecf 100644
--- a/core/php7.3Action/CHANGELOG.md
+++ b/core/php7.3Action/CHANGELOG.md
@@ -19,6 +19,8 @@
 ## Apache 1.14.0-incubating (next release)
 Changes:
   - Update version of PHP to 7.3.5
+  - Added PHP extension mongodb
+
 
 ## Apache 1.13.0-incubating
 Initial release
diff --git a/core/php7.3Action/Dockerfile b/core/php7.3Action/Dockerfile
index 1088032..f9cf261 100644
--- a/core/php7.3Action/Dockerfile
+++ b/core/php7.3Action/Dockerfile
@@ -51,7 +51,9 @@
       pdo_mysql \
       pdo_pgsql \
       soap \
-      zip
+      zip \
+      && pecl install mongodb \
+      && docker-php-ext-enable mongodb
 
 COPY php.ini /usr/local/etc/php