fix typings

[jeetiss]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

its bugfix

• What is the current behavior? (You can also link to an open issue here)

npm run build throws some errors about 'client' does not exist in type 'ClientInterface'. after merge #9

• What is the new behavior (if this is a feature change)?

All works nice

• Other information:

nope

[jemgold]

Thank you! This should be live in 1.6.1 :)