Add failing test for Dot visitor and BindParam
Add failing test for Dot visitor and BindParam

Since BindParam has no value, treating it like a string
causes it to fallback to Object#to_s, leading to output like
`#<Arel::Nodes::BindParam:0x007fa43c866108>`.

Since angle brackets are significant in Dot labels, this causes
`Error: bad label format` when passing the graph into dot.

rails/rails,untidy-hair/rails,baerjam/rails,prathamesh-sonpatki/rails,rafaelfranca/omg-rails,esparta/rails,aditya-kapoor/rails,Vasfed/rails,EmmaB/rails-1,illacceptanything/illacceptanything,printercu/rails,BlakeWilliams/rails,eileencodes/rails,Envek/rails,shioyama/rails,iainbeeston/rails,rails/rails,yahonda/arel,yahonda/rails,Edouard-chin/rails,baerjam/rails,illacceptanything/illacceptanything,untidy-hair/rails,notapatch/rails,ngpestelos/arel,repinel/rails,joonyou/rails,joonyou/rails,palkan/rails,aditya-kapoor/rails,prathamesh-sonpatki/rails,untidy-hair/rails,betesh/rails,utilum/rails,utilum/rails,georgeclaghorn/rails,yalab/rails,illacceptanything/illacceptanything,fabianoleittes/rails,betesh/rails,fabianoleittes/rails,arunagw/rails,illacceptanything/illacceptanything,repinel/rails,iainbeeston/rails,mechanicles/rails,kmcphillips/rails,jeremy/rails,georgeclaghorn/rails,eileencodes/rails,illacceptanything/illacceptanything,ngpestelos/arel,notapatch/rails,Erol/rails,kmcphillips/rails,deraru/rails,Edouard-chin/rails,yhirano55/rails,schuetzm/rails,yawboakye/rails,starknx/rails,fabianoleittes/rails,mechanicles/rails,Envek/rails,bogdanvlviv/rails,illacceptanything/illacceptanything,mechanicles/rails,aditya-kapoor/rails,flanger001/rails,notapatch/rails,illacceptanything/illacceptanything,kbrock/arel,tjschuck/rails,repinel/rails,yawboakye/rails,assain/rails,Vasfed/rails,repinel/rails,bogdanvlviv/rails,MSP-Greg/rails,shioyama/rails,gauravtiwari/rails,Erol/rails,rafaelfranca/omg-rails,shioyama/rails,vipulnsward/rails,georgeclaghorn/rails,yawboakye/rails,Vasfed/rails,deraru/rails,deraru/rails,lcreid/rails,starknx/rails,MSP-Greg/rails,pvalena/rails,utilum/rails,Envek/rails,mohitnatoo/rails,schuetzm/rails,BlakeWilliams/rails,joonyou/rails,prathamesh-sonpatki/rails,illacceptanything/illacceptanything,arunagw/rails,arunagw/rails,EmmaB/rails-1,arunagw/rails,palkan/rails,Erol/rails,illacceptanything/illacceptanything,joonyou/rails,Erol/rails,lcreid/rails,kmcphillips/rails,rails/arel,assain/rails,schuetzm/rails,flanger001/rails,untidy-hair/rails,bogdanvlviv/rails,betesh/rails,tjschuck/rails,yahonda/arel,vipulnsward/rails,Edouard-chin/rails,yahonda/rails,iainbeeston/rails,shioyama/rails,baerjam/rails,Stellenticket/rails,tgxworld/rails,baerjam/rails,illacceptanything/illacceptanything,mohitnatoo/rails,tgxworld/rails,kddeisz/rails,yalab/rails,Stellenticket/rails,rails/rails,palkan/rails,MSP-Greg/rails,rafaelfranca/omg-rails,eileencodes/rails,lcreid/rails,vipulnsward/rails,starknx/rails,kmcphillips/rails,BlakeWilliams/rails,esparta/rails,kbrock/arel,kddeisz/rails,fabianoleittes/rails,yhirano55/rails,esparta/rails,tgxworld/rails,esparta/rails,yahonda/rails,lcreid/rails,EmmaB/rails-1,notapatch/rails,yhirano55/rails,mechanicles/rails,MSP-Greg/rails,pvalena/rails,printercu/rails,illacceptanything/illacceptanything,bogdanvlviv/rails,Envek/rails,gauravtiwari/rails,mohitnatoo/rails,betesh/rails,gauravtiwari/rails,kddeisz/rails,jeremy/rails,eileencodes/rails,pvalena/rails,pvalena/rails,yalab/rails,tjschuck/rails,illacceptanything/illacceptanything,Vasfed/rails,flanger001/rails,jeremy/rails,Stellenticket/rails,yhirano55/rails,Stellenticket/rails,georgeclaghorn/rails,assain/rails,flanger001/rails,Edouard-chin/rails,illacceptanything/illacceptanything,yalab/rails,iainbeeston/rails,aditya-kapoor/rails,deraru/rails,illacceptanything/illacceptanything,assain/rails,printercu/rails,utilum/rails,illacceptanything/illacceptanything,rails/rails,prathamesh-sonpatki/rails,kddeisz/rails,palkan/rails,jeremy/rails,printercu/rails,BlakeWilliams/rails,mohitnatoo/rails,vipulnsward/rails,tgxworld/rails,yawboakye/rails,schuetzm/rails,yahonda/rails,tjschuck/rails