ppc64el and i386 unittests cannot find tools

[Curtis Hovey]

bootstrapSuite.TestBootstrapNoTools fails for both of these architectures in devel
     http://juju-ci.vapour.ws:8080/job/run-unit-tests-precise-i386/560/console
    http://juju-ci.vapour.ws:8080/job/run-unit-tests-trusty-ppc64el/1095/console

The last successful run for devel was master commit 27007968. The first failure is master commit b2839163.
    c9d4753 Merge pull request #563 from howbazaar/remove-legacy-upgrade-code
    0f74c61 Merge pull request #568 from howbazaar/fix-envcmd-ensure
    e31625f Merge pull request #566 from mjs/write-upgradedToVersion-even-when-no-upgrade
    cf54c8b Merge pull request #571 from davecheney/183-state-apiserver-keymanager-canread-is
    e31625f Merge pull request #574 from wallyworld/use-floatingip-as-public-address
    2c66731 Merge pull request #557 from axw/environ-bootstrap-upload-tools
    b283916 Merge pull request #581 from mattyw/metric-uuid-fix

I suspect commit 2c66731 is the problem.