writing convention set to use "." to source script files

refer to:
https://docs.openstack.org/contributor-guide/writing-style/ \
code-conventions.html

Change-Id: I25bc8a60413b2afb2dd33b79913a29f2764a695e

doc/source/admin/troubleshooting-guide.rst

@@ -134,7 +134,7 @@ and the domain admin:
 
 .. code-block:: bash
 
-    source /opt/stack/devstack/accrc/admin/admin
+    . /opt/stack/devstack/accrc/admin/admin
     export OS_IDENTITY_API_VERSION=3
     unset OS_AUTH_TYPE
     openstack domain create magnum
@@ -142,7 +142,7 @@ and the domain admin:
         --domain=magnum
     openstack role add --user=trustee_domain_admin --user-domain magnum --domain=magnum admin
 
-    source /opt/stack/devstack/functions
+    . /opt/stack/devstack/functions
     export MAGNUM_CONF=/etc/magnum/magnum.conf
     iniset $MAGNUM_CONF trust trustee_domain_id \
         $(openstack domain show magnum | awk '/ id /{print $4}')
@@ -487,7 +487,7 @@ If etcd continues to fail, check the following:
   cause of failure is that this public discovery service is not
   reachable.  Check by running on the master nodes::
 
-    source /etc/sysconfig/heat-params
+    . /etc/sysconfig/heat-params
     curl $ETCD_DISCOVERY_URL
 
   You should receive something like::
@@ -763,7 +763,7 @@ Simulating gate tests
       }
       export -f gate_hook
       function post_test_hook {
-          source $BASE/new/devstack/accrc/admin/admin
+          . $BASE/new/devstack/accrc/admin/admin
           cd /opt/stack/new/magnum/
           ./magnum/tests/contrib/post_test_hook.sh api # change this to swarm to run swarm functional tests or k8s to run kubernetes functional tests
       }

doc/source/contributor/functional-test.rst

@@ -32,27 +32,27 @@ If you're using devstack, you can copy and modify the devstack configuration::
     sed -i "s/127.0.0.1/$HOST/" functional_creds.conf
 
     # update admin password
-    source /opt/stack/devstack/openrc admin admin
+    . /opt/stack/devstack/openrc admin admin
     iniset functional_creds.conf admin pass $OS_PASSWORD
 
     # update demo password
-    source /opt/stack/devstack/openrc demo demo
+    . /opt/stack/devstack/openrc demo demo
     iniset functional_creds.conf auth password $OS_PASSWORD
 
 Set the DNS name server to be used by your cluster nodes (e.g. 8.8.8.8)::
 
     # update DNS name server
-    source /opt/stack/devstack/openrc demo demo
+    . /opt/stack/devstack/openrc demo demo
     iniset functional_creds.conf magnum dns_nameserver <dns-svr-ip-address>
 
 Create the necessary keypair and flavor::
 
-    source /opt/stack/devstack/openrc admin admin
+    . /opt/stack/devstack/openrc admin admin
     openstack keypair create --public-key ~/.ssh/id_rsa.pub  default
     openstack flavor create --id 100 --ram 1024 --disk 10 --vcpus 1 m1.magnum
     openstack flavor create --id 200 --ram 512 --disk 10 --vcpus 1 s1.magnum
 
-    source /opt/stack/devstack/openrc demo demo
+    . /opt/stack/devstack/openrc demo demo
     openstack keypair create --public-key ~/.ssh/id_rsa.pub  default
 
 You may need to explicitly upgrade required packages if you've installed them

doc/source/contributor/quickstart.rst

@@ -193,7 +193,7 @@ Prepare your session to be able to use the various openstack clients including
 magnum, neutron, and glance. Create a new shell, and source the devstack openrc
 script::
 
-    source /opt/stack/devstack/openrc admin admin
+    . /opt/stack/devstack/openrc admin admin
 
 Magnum has been tested with the Fedora Atomic micro-OS and CoreOS. Magnum will
 likely work with other micro-OS platforms, but each requires individual

doc/source/user/cluster-type-definition.rst

@@ -44,7 +44,7 @@ Enabling a Cluster Type is as simple as adding it's Entry Point to the
     # Setup python environment and install Magnum
 
     $ virtualenv .venv
-    $ source .venv/bin/active
+    $ . .venv/bin/active
     (.venv)$ git clone https://github.com/openstack/magnum.git
     (.venv)$ cd magnum
     (.venv)$ python setup.py install