Change docker installation instructions

readme.md

@@ -21,11 +21,12 @@ git checkout develop
 
 ### Installing Docker
 
-Install docker and docker-compose. On Ubuntu this can be done with
+Install docker and docker-compose. On Ubuntu you can install ocker from the repositories but docker-compose must be installed separately.
 
 ```BASH
-sudo apt-get install docker docker-compose
+sudo apt-get install docker
 ```
+Navigate to [docker-compose releases](https://github.com/docker/compose/releases) for install information.
 
 ### Configuring db image
 
@@ -36,7 +37,7 @@ sudo docker-compose up db
 Then configure following with another shell window
 ```BASH
 sudo docker exec -ti <image_name> bash  # image name can be found with sudo docker ps (probably web20_db_1)
-mysql -u root -p                        # then enter root password which can be found in docker-compose.yml
+mysql -u root -p                        # then enter root password ("toor" by default) which can be found in docker-compose.yml 
 ```
 
 ```SQL