table_exists deprecation warning

[mahemoff]

I got this running LHM on a Rails 5 app.

DEPRECATION WARNING: #table_exists? currently checks both tables and views. This behavior is deprecated and will be changed with Rails 5.1 to only check tables. Use #data_source_exists? instead.

I notice table_exists? is indeed present in LHM, so maybe it's just a matter of find-replace?