Start OMERO 4.4.8p1 instance as part of the Travis build
Run db script to start OMERO in Travis build
Unzip server in quiet mode and do not cd to run subsequent tests
Merge branch 'master' of https://github.com/ome/omero-setup into upgrade_travis
Activate upgrade integration test
Set psql operation in quiet mode
Set unzipargs to use quiet mode in testUpgrade
Switch to urllib2 to read URLs and download artifacts

This allows an easier customization of the opening request header. This PR
also allows to set the download user-agent using the USER_AGENT environment
variable.
Pass user agent to the Travis build by envvar and use with wget

Also remove debugging line in omego/artifacts.py
Merge pull request #14 from sbesson/upgrade_travis

Test `omego upgrade` as part of the Travis build