* misc fixes for 2.4.0rc7:
- warcserver: when parsing headers to check for redirect, reserialized headers
may be of different length then original, causing warcserver->app response to hang
now adjusting the content-length on the warc record and also not including a fixed
length when serving warcserver->app, possible fix for ukwa/ukwa-pywb#53
- undo change in path resolvers to use os.path.join, just concatenate full_path + filename
- rewrite 'date' -> 'x-orig-archive-date' header to avoid confusion (eg. #548)
- bump version to rc7
* ci: attempt to fix travis build for 27, 35
update pip and setuptools when running install.sh found in .travis
use xenial
removed trailing dash
only run webrecorder-tests using chrome and firefox
only run webrecorder-tests using pywbtest and chrometest marker expression
New integration tests using webrecorder-tests:
- WR_TEST=true is set for integration test run (only run with py3.6, excluded for py2.7, 3.5)
- Added .travis directory that includes two scripts: install.sh and test.sh.
- install.sh handles all installation and test.sh handles running of unit or integration tests
- sudo: true required to run headless chrome
