cmd: add go_term_enabled for :GoTest .. commands
cmd: add go_term_enabled for :GoTest .. commands

This enables us to change the way how GoTest is executed

t-yuki/vim-go,ebfe/vim-go,wheelcomplex/vim-go,andviro/vim-go,vim-IDE/vim-go,andviro/vim-go,vim-IDE/vim-go,vim-IDE/vim-go