Don't set scalaVersion in build script

Author: ashawley

build.sh

@@ -68,9 +68,7 @@ if [[ "$TRAVIS_TAG" =~ $tagPat ]]; then
       exit 0
     fi
   else
-    if isTagScalaReleaseJob; then
-      setTagScalaVersion='set every scalaVersion := "'$tagScalaVer'"'
-    else
+    if ! isTagScalaReleaseJob; then
       echo "The releases for Scala $tagScalaVer are built by other jobs in the travis job matrix"
       exit 0
     fi