Small improvements to development dockerfile (#422)

* remove --force-polling from jekyll command
* remove exclude tag from config file for simplicity
diff --git a/Dockerfile b/Dockerfile
index 3554c0b..2798588 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -31,4 +31,4 @@
 EXPOSE $PORT
 
 # Configure the default command to build from the mounted repository.
-CMD bundle exec jekyll serve --force-polling -H $HOST -P $PORT
+CMD bundle exec jekyll serve -H $HOST -P $PORT
diff --git a/_config.yml b/_config.yml
index 845d17e..5baea8d 100644
--- a/_config.yml
+++ b/_config.yml
@@ -13,7 +13,6 @@
   The Apache Accumulo™ sorted, distributed key/value store is a robust, scalable,
   high performance data storage and retrieval system.
 url: "https://accumulo.apache.org" # the base hostname & protocol for your site
-exclude: [vendor]
 latest_release: 2.1.2
 javadoc_version: 2.1.2
 num_home_posts: 5