Installation script should report error when extensions fail to load

[tst-jhaight]

Installing geserver has been found to report success incorrectly in certain situations when an extension fails to load correctly. This can cause the user to believe the geserver service is installed and running when there are really installation issues which need to be corrected.

Reproduction steps (done on Ubuntu 16.04):

1. Create an Ubuntu 16.04 VM which does not have all prerequisite build packages installed.
2. On a 2nd Ubuntu 16.04 machine obtain the earthenterprise source code and follow instructions to build and stage an install
3. Verify that the build, execution of unit tests, and staging of the installer completes without errors
4. Create a compressed archive of the installation bundle:
   cp -R earthenterprise/earth_enterprise/src/installer/ /tmp/fusion_os_install/ tar cvfJ opengee-server-fusion-<version>.tar.xz /tmp/fusion_os_install
5. Copy opengee-server-fusion-.tar.xz to a location from which you can transfer it to target install machines.
6. On the target install machine untar and install the packages.
7. Installation will report some missing dependencies, install those reported as missing.
8. Retry installation and observe the following

• The script output contains error the command executing at the time of the error was "$BINDIR/psql" -U geuser -d gepoi -c "CREATE EXTENSION postgis"
• Installation completes with a message saying Congratulations! Google Earth Enterprise has been successfully installed in the following directory