added connection logoff when exiting
added connection logoff when exiting

vonahnen/ruby-plsql-spec,rsim/ruby-plsql-spec,rsim/ruby-plsql-spec,jgebal/ruby-plsql-spec,vonahnen/ruby-plsql-spec,rsim/ruby-plsql-spec,jgebal/ruby-plsql-spec,vonahnen/ruby-plsql-spec,rsim/ruby-plsql-spec,vonahnen/ruby-plsql-spec,jgebal/ruby-plsql-spec