install_dependencies.sh: update centos package list and example
install_dependencies.sh: update centos package list and example

Add missing packages to `yum install` list:
* scylla-boost163-static
* scylla-python34-pyparsing20

Update the configure.py example so that it just works:
* Change g++ to 7.3
* Add --with-antlr3 pointing to antlr3 installed from scylla 3rdparty

scylladb/scylla,duarten/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,duarten/scylla,duarten/scylla,avikivity/scylla