Add a showListMemberships param to Hubspot::Contact.find_by_email

[dventulieri]

The showListMemberships param is set to false by default by HubSpot when getting contacts by a batch of email addresses. My use case requires getting contact lists based on an array of email addresses. However, when I call Hubspot::Contact.find_by_email([email1, email2]), no contact list data is returned because we are not setting the showListMemberships param.

We can get around this by adding showListMemberships: true to the parameters on the following line: https://github.com/adimichele/hubspot-ruby/blob/d9a369eb2aacda5a87b7de46942dec3e774e191b/lib/hubspot/contact.rb#L113

i.e. :

when Array then [true, GET_CONTACTS_BY_EMAIL_PATH, { batch_email: emails, showListMemberships: true }]

Would it be possible to add a showListMemberships parameter to the method so we can specify if we need lists or not?

Otherwise, I need to call Hubspot::Connection.get( ... ) directly. I would prefer to use the Hubspot::Contact.find_by_email method of course.

Thanks!

[dventulieri]

PR: #184