Update installation.md

Author: rjeberhard

site/installation.md

@@ -21,7 +21,7 @@ First run the build using this command:
 mvn clean install
 ```
 
-Then log in to Docker Store so that you will be able to pull the base image, and create the Docker image as follows:
+Then login to Docker Store so that you will be able to pull the base image, and create the Docker image as follows:
 
 ```
 docker login