First, take the exclusive lock that ensures only one running binary
later: after assembling the gotest.app directory and signing it.

Second, don't pass -r to ios-deploy. The -r flag uninstalls the
app before installing it. It seems unnecessary, takes extra time
and if there was only the one developer app on the phone, it
will drop the developer permission on uninstall.

Change-Id: Ia222d3e5c2e1e2285f53074eb952941fd45fadd9
Reviewed-on: https://go-review.googlesource.com/106676Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>