Fix parsing bug in 'mixer build bundles'

The recent change in 'mixer build bundles' contained a parsing bug that
caused some packages to be dropped. The way 'dnf install' output was
split caused the regex to miss the final line on some bundles. This
patch fixes this bug.

Signed-off-by: Kevin C. Wells <kevin.c.wells@intel.com>

builder/bundles.go

@@ -272,8 +272,8 @@ func resolveFiles(numWorkers int, set bundleSet, bundleRepoPkgs map[string]map[s
 // NO-OP INSTALL OUTPUT EXAMPLE
 // Truncated at 80 characters to make it more readable, but the full output is a
 // five-column list of Package, Arch, Version, Repository, and Size.
-// The section we care about is everything from "Installing:" to the next blank
-// line.
+// The section we care about is everything from "Installing:" to "Transaction
+// Summary"
 //
 // Last metadata expiration check: 0:00:00 ago on Wed 07 Mar 2018 04:05:44 PM PS
 // Dependencies resolved.
@@ -309,7 +309,7 @@ func parseNoopInstall(installOut string) map[string][]string {
 
 	// Split out the section between the install list and the transaction Summary
 	pkgList := strings.Split(installOut, "Installing:\n")[1]
-	pkgList = strings.Split(pkgList, "\n\nTransaction Summary")[0]
+	pkgList = strings.Split(pkgList, "\nTransaction Summary")[0]
 
 	// When not running in a TTY, dnf sets terminal line-width to a default 80
 	// characters, then wraps their fields in an unpredictable way to be