fix bin path when starting node and wallet. We're now adding BINS to …

…the PATH but absolute path is still needed when starting node and wallet as services on Win.

test/e2e/Rakefile

@@ -108,7 +108,7 @@ end
 task :start_node_and_wallet, [:env] do |task, args|
   puts "\n  >> Setting up cardano-node and cardano-wallet"
 
-  bin_dir = BINS
+  bin_dir = BINS == '' ? BINS : "#{BINS}/"
   config_dir = File.join(CONFIGS, args[:env])
   cd = Dir.pwd
   mk_dir(STATE)