Improve README.rst formatting

Change-Id: I7f14fc263b63c31ee5f9863cd0508e830900e31a

README.rst

@@ -9,6 +9,8 @@ Developer setup
 
 Install dependencies:
 
+.. code-block:: bash
+
     sudo apt-get install git mysql-server libmysqlclient-dev g++ python-dev libzmq-dev
     mkdir src
     cd ~/src
@@ -22,6 +24,8 @@ If you're testing a specific patch that is already in gerrit, you will also
 want to install git-review and apply that patch while in the nodepool
 directory, ie:
 
+.. code-block:: bash
+
     git review -x XXXXX
 
 If the cloud being used has no default_floating_pool defined in nova.conf,
@@ -29,6 +33,8 @@ you will need to define a pool name using nodepool.layout to use floating ips.
 
 Set up database:
 
+.. code-block:: bash
+
     mysql -u root
 
     mysql> create database nodepool;
@@ -37,11 +43,15 @@ mysql> flush privileges;
 
 Export variable for your ssh key so you can log into the created instances:
 
+.. code-block:: bash
+
     export NODEPOOL_SSH_KEY=`cat ~/.ssh/id_rsa.pub`
 
 Start nodepool with a demo config file (copy or edit fake.yaml
 to contain your data):
 
+.. code-block:: bash
+
     export STATSD_HOST=127.0.0.1
     export STATSD_PORT=8125
     nodepoold -d -c tools/fake.yaml
@@ -50,8 +60,12 @@ All logging ends up in stdout.
 
 Use the following tool to check on progress:
 
+.. code-block:: bash
+
     nodepool image-list
 
 After each run (the fake nova provider is only in-memory):
 
+.. code-block:: bash
+
     mysql> delete from snapshot_image; delete from node;