Clarify trailing slash for PIPE_DIR
Clarify trailing slash for PIPE_DIR

The trailing slash for PIPE_DIR is necessary for
both start and attach operations.

sile/rebar3,blt/rebar3,beni55/rebar,djnym/rebar3,heroku/rebar,erlang/rebar3,choptastic/rebar,csyangchen/rebar,norton/rebar,lpgauth/rebar,bsmr-erlang/rebar,macintux/rebar,bsmr-erlang/rebar,ferd/rebar3,deadok22/rebar,wcy123/rebar,matwey/rebar,dcarastan/rebar,oubiwann/rebar,csyangchen/rebar,shkumagai/rebar,bsmr-erlang/rebar,matwey/rebar,syl20bnr/rebar,lpgauth/rebar,fauxsoup/rebar3,surik/rebar3,cloudant/couchdb-rebar,fauxsoup/rebar3,GabrielNicolasAvellaneda/rebar,lrascao/rebar3,thomasbhatia/rebar,paulo-ferraz-oliveira/rebar,lpgauth/rebar,syl20bnr/rebar,platinumthinker/rebar,lrascao/rebar,oubiwann/rebar,jacktang/rebar,platinumthinker/rebar,GabrielNicolasAvellaneda/rebar,syl20bnr/rebar,walrusVision/rebar3,kellymclaughlin/rebar3,jbalint/rebar3,basho/rebar,CMoH/rebar,linearregression/rebar3,walrusVision/rebar3,macintux/rebar,bsmr-erlang/rebar,rebar/rebar3,rebar/rebar,jacktang/rebar,evnix/rebar,beni55/rebar,K2InformaticsGmbH/rebar,K2InformaticsGmbH/rebar,oubiwann/rebar,rebar/rebar,rebar/rebar,apache/couchdb-rebar,benoitc/rebar3,linearregression/rebar3,paulo-ferraz-oliveira/rebar,scatterbrain/rebar,beni55/rebar-1,lrascao/rebar,apache/couchdb-rebar,norton/rebar,scatterbrain/rebar,dcarastan/rebar,fishcakez/rebar3,SiDen/rebar,norton/rebar,matwey/rebar,processone/rebar3,thomasbhatia/rebar,vladdu/rebar3,scatterbrain/rebar,evnix/rebar,tsloughter/rebar3,choptastic/rebar,paulo-ferraz-oliveira/rebar,CMoH/rebar,benoitc/rebar3,macintux/rebar,cloudant/couchdb-rebar,lrascao/rebar,lrascao/rebar,matwey/rebar,thomasbhatia/rebar,apache/couchdb-rebar,saleyn/rebar3,csyangchen/rebar,CMoH/rebar,RubberCthulhu/rebar,deadok22/rebar,project-fifo/rebar3,K2InformaticsGmbH/rebar,shkumagai/rebar,choptastic/rebar,rebar/rebar3,wcy123/rebar,zugolosian/rebar3,platinumthinker/rebar,surik/rebar3,matwey/rebar,RubberCthulhu/rebar,cloudant/couchdb-rebar,heroku/rebar,fabiankrol/rebar3,evnix/rebar,SiDen/rebar,basho/rebar,blt/rebar3,sile/rebar3,zugolosian/rebar3,SiDen/rebar,shkumagai/rebar,jbalint/rebar3,K2InformaticsGmbH/rebar,K2InformaticsGmbH/rebar,fabiankrol/rebar3,jacktang/rebar,processone/rebar3,beni55/rebar-1,norton/rebar3,dcarastan/rebar,lrascao/rebar,project-fifo/rebar3,GabrielNicolasAvellaneda/rebar,beni55/rebar,norton/rebar