At page 6 it says to use the trunk version that is the 1.2.0-SNAPSHOT at the moment with very different requirements (JDK 9, Maven 3.5, etc...)
svn checkout http://svn.apache.org/repos/asf/chemistry/opencmis/trunk
Instead I'm using the version 1.1.0 and its working
svn checkout http://svn.apache.org/repos/asf/chemistry/opencmis/tags/chemistry-opencmis-1.1.0