Update dependencies after joi was split out

[abeluck]

We need to undo some of the changes in #41:

warning blipp > @hapi/hoek@8.5.1: This version has been deprecated and is no longer supported or maintained
warning blipp > @hapi/joi@15.1.1: Switch to 'npm install joi'
warning blipp > @hapi/joi > @hapi/bourne@1.3.2: This version has been deprecated and is no longer supported or maintained
warning blipp > @hapi/joi > @hapi/hoek@8.5.1: This version has been deprecated and is no longer supported or maintained
warning blipp > @hapi/joi > @hapi/topo@3.1.6: This version has been deprecated and is no longer supported or maintained
warning blipp > @hapi/joi > @hapi/topo > @hapi/hoek@8.5.1: This version has been deprecated and is no longer supported or maintained
warning blipp > @hapi/joi > @hapi/address@2.1.4: Moved to 'npm install @sideway/address'

• @hapi/joi -> joi
• Bump @hapi/hoek to latest