Travis: Use 4.1.1 instead of 4.1.0

... only the latest is the greatest.

Author: helje5

.travis.yml

@@ -11,7 +11,7 @@ matrix:
           sudo: required
         - os:   Linux
           dist: trusty
-          env:  SWIFT_SNAPSHOT_NAME="https://swift.org/builds/swift-4.1-release/ubuntu1404/swift-4.1-RELEASE/swift-4.1-RELEASE-ubuntu14.04.tar.gz"
+          env:  SWIFT_SNAPSHOT_NAME="https://swift.org/builds/swift-4.1.1-release/ubuntu1404/swift-4.1.1-RELEASE/swift-4.1.1-RELEASE-ubuntu14.04.tar.gz"
           sudo: required
         - os:   Linux
           dist: trusty