Quick start guide fix

[alexandrasandulescu]

Hello. Here is a fix for the 'quick start guide' - building section.

mkdir ./measure-agent
-> cd ./measure-agent
-> git clone https://github.com/ITEA3-Measure/MeasureAgent.git
+> git clone https://github.com/ITEA3-Measure/MeasureAgent.git measure-agent
+> cd measure-agent
mvn package

Can you grant pull request access for external users?
thank you