use hmac.compare_digest if available
Make sure tox fails the cover build if it isn't at 100%
Merge pull request #1458 from sontek/fail_coverage_under_hundred

Make sure tox fails the cover build if it isn't at 100%
Switch to using tox for travis so coverage is ran
Merge pull request #1457 from Pylons/feature.string-timing-attacks

use hmac.compare_digest if available
Use travis_retry in case of timeouts, remove -e $OTX_ENV
Merge pull request #1459 from sontek/use_tox_for_travis

Switch to using tox for travis so coverage is ran
fix travis.yml to use the correct TOXENV var
Merge branch 'master' into feature.security-docs-enhancements