Add metrics for etherpad

pica-eterpad/Dockerfile

@@ -21,9 +21,21 @@ RUN bin/installDeps.sh && rm settings.json
 RUN ln -s var/settings.json settings.json
 
 # Installation modules Etherpad
-RUN npm install ep_align && npm install ep_author_hover && npm install ep_comments_page && npm install ep_countable && \
-    npm install ep_delete_empty_pads && npm install ep_font_color && npm install ep_headings2 && npm install ep_markdown && \
-    npm install ep_page_view && npm install ep_spellcheck && npm install ep_subscript_and_superscript && npm install ep_table_of_contents && npm install ep_user_font_size
+RUN npm install \
+        ep_align \
+        ep_author_hover \
+        ep_comments_page \
+        ep_countable \
+        ep_delete_empty_pads \
+        ep_font_color \
+        ep_headings2 \
+        ep_markdown \
+        ep_page_view \
+        ep_spellcheck \
+        ep_subscript_and_superscript \
+        ep_table_of_contents \
+        ep_user_font_size \
+        ep_pads_stats
 
 #Copy configuration
 COPY add/entrypoint.sh /entrypoint.sh