Fix encoding issue with tests.

This was causing test failures when the LANG etc. env variables weren't
set (e.g. on the new CI environment).
Remove Gemfile.lock before running tests.

This ensures we're testing against the dependencies specified in the
gemsepc.
move report-a-problem to new endpoint in support app
support app: move report-a-problem endpoint

/problem_reports => /anonymous_feedback/problem_reports
Use default jsonclient headers.
Update fact_cave test helpers to support different types
Version bump to 7.6.0
Merge pull request #13 from theodi/gds_upgrade_to_7.6.0

Gds upgrade to 7.6.0