Exiting out of onboarding flow takes the user to their profile

[jmgasper]

REF: https://topcoder.atlassian.net/browse/MP-187

When the user has completed the onboarding flow, if they click 'Next' or 'Finish', they should be taken to their profile page at:

• profiles.{domain}/{handle}

Examples:

• profiles.topcoder-dev.com/onboarding103
• profiles.topcoder.com/Ghostar

[suppermancool]

@jmgasper done in #707