Assert URLs shouldn't consider slash in the end

[diegolovison]

The following URL must match. Today it is failing
"url": "https://docs.pachyderm.com/latest/getting_started/"
"url": "https://docs.pachyderm.com/latest/getting-started"

See: #712

Running a test:

ODS_CI_RUN_SCRIPT_ARGS=--test-case ods_ci/tests/Tests/400__ods_dashboard/400__ods_dashboard.robot --set-urls-variables true --extra-robot-args '-L DEBUG' --skip-oclogin