do not install chart-observe script for analysis-only installs

[adampbeardsley]

Right now our setup.py adds the chart-observe script around here:

CHART/setup.py

Line 40 in 7e5ae7b

launcher = os.path.expanduser("~/Desktop/chart-observe")

But if someone just wants the analysis code, they shouldn't need this. And it has broken the pip install for at least one user.