Simplify docs by removing default "latest" tag (#269)

docs/source/installing-server.md

@@ -121,7 +121,7 @@ Assuming you have Docker installed, you would proceed as follows.
 
 In a terminal shell, pull the latest version of the BigchainDB Docker image using:
 ```text
-docker pull bigchaindb/bigchaindb:latest
+docker pull bigchaindb/bigchaindb
 ```
 
 then do a one-time configuration step to create the config file; we will use
@@ -130,7 +130,7 @@ be stored in a file on your host machine at `~/bigchaindb_docker/.bigchaindb`:
 
 ```text
 $ docker run --rm -v "$HOME/bigchaindb_docker:/data" -ti \
-  bigchaindb/bigchaindb:latest -y configure
+  bigchaindb/bigchaindb -y configure
 Generating keypair
 Configuration written to /data/.bigchaindb
 Ready to go!
@@ -147,7 +147,7 @@ Let's analyze that command:
  documentation](https://docs.docker.com/engine/userguide/containers/dockervolumes/#mount-a-host-directory-as-a-data-volume)
 * `-t` allocate a pseudo-TTY
 * `-i` keep STDIN open even if not attached
-* `bigchaindb/bigchaindb:latest` the image to use
+* `bigchaindb/bigchaindb the image to use
 * `-y configure` execute the `configure` sub-command (of the `bigchaindb` command) inside the container, with the `-y` option to automatically use all the default config values
 
 
@@ -157,7 +157,7 @@ After configuring the system, you can run BigchainDB with the following command:
 $ docker run -v "$HOME/bigchaindb_docker:/data" -d \
   --name bigchaindb \
   -p "58080:8080" -p "59984:9984" \
-  bigchaindb/bigchaindb:latest start
+  bigchaindb/bigchaindb start
 ```
 
 The command is slightly different from the previous one, the differences are:
@@ -200,7 +200,7 @@ You can load test the BigchainDB running in that container by running the `bigch
 ```text
 $ docker run --rm -v "$HOME/bigchaindb_docker:/data" -ti \
   --link bigchaindb \
-  bigchaindb/bigchaindb:latest load
+  bigchaindb/bigchaindb load
 ```
 
 Note the `--link` option to link to the first container (named `bigchaindb`).