compose config fixes, doc correction

docker-compose.yml

@@ -3,15 +3,17 @@ version: '3'
 services:
   web:
     image: martel/mastermind-ui
-    #environment:
-      #- MASTERMIND_API_URI='http://localhost:3000'
+    environment:
+      - MASTERMIND_API_HOST='localhost'
+      - MASTERMIND_API_PORT='3000'
     ports:
       - "8080:8080"
 
   api:
     image: martel/mastermind-api
-    #environment:
-      #- SERVICE_MANAGER_URI='http://service-manager:8081'
+    environment:
+      - SERVICE_MANAGER_HOST='service-manager'
+      - SERVICE_MANAGER_PORT='8080'
     ports:
       - "3000:3000"
     command: rails s -b0

docs/admin/installation.md

@@ -37,8 +37,10 @@ The service's default configuration can be overriden through the use of a few
 environment variables:
 
 - MASTERMIND_VERSION: the current version of MasterMind
-- SERVICE_MANAGER_URI: the URI of MasterMind's Service Manager Microservice,
-  port and protocol included (e.g. <http://service-manager:8081>)
+- SERVICE_MANAGER_HOST: the host of MasterMind's Service Manager Microservice,
+  (e.g. service-manager)
+- SERVICE_MANAGER_PORT: the port of MasterMind's Service Manager Microservice,
+  (e.g. 8080)
 
 ## Service Manager
 
@@ -96,5 +98,7 @@ The UI's default configuration can be overriden through the use of a few
 environment variables:
 
 - MASTERMIND_VERSION: the current version of MasterMind
-- MASTERMIND_API_URI: the URI of MasterMind's API, port and protocol included
-  (e.g. <http://localhost:3000>)
+- MASTERMIND_API_HOST: the host of MasterMind's API
+  (e.g. localhost)
+- MASTERMIND_API_PORT: the port of MasterMind's API
+  (e.g. 3000)