Add myself to Source/modules/payments/OWNERS

Change-Id: Ic7eebc07a3fec115130c7de70b8571385bdd04f0
Reviewed-on: https://chromium-review.googlesource.com/812024Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Jinho Bang <jinho.bang@samsung.com>
Cr-Commit-Position: refs/heads/master@{#522189}

third_party/WebKit/Source/modules/payments/OWNERS

 # TEAM: paymentrequest@chromium.org
 # COMPONENT: Blink>Payments
 
+jinho.bang@samsung.com
 mathp@chromium.org
 mek@chromium.org
 rouslan@chromium.org