Handle when select succeeds, but there's nothing to gets

Author: technicalpickles

Diff for: lib/spring/client/run.rb

@@ -118,7 +118,12 @@ def verify_server_version
           raise "Error connecting to Spring server"
         end
 
-        server_version = server.gets.chomp
+        line = server.gets
+        unless line
+          raise "Error connecting to Spring server"
+        end
+
+        server_version = line.chomp
         if server_version != env.version
           $stderr.puts "There is a version mismatch between the Spring client " \
                          "(#{env.version}) and the server (#{server_version})."