Increase tabris clean test suite timeout
Increase tabris clean test suite timeout

"removes build/cordova folder" timeouted on Travis CI. Increase the
timeout of the suite to 10s to accomodate slow fs operations.

Change-Id: I3a2edd6c8330b40c7b217eec1443ea0fad2d9380

eclipsesource/tabris-js-cli