Ignore .pyc in client/.
Ignore .pyc in client/.

It is there so github.com/luci/client-py has it in its root when exported from
client/.

R=tandrii@chromium.org
BUG=chromium:555827

Review URL: https://codereview.chromium.org/1470093003

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py