Fix Write-PesterStart to allow hashtables in $Path

Fix for:
 - Unexpected output when passing hashtable to Invoke-Pester pester#699
 - Bug in output where multiple Paths are passed in to -Scripts at Invoke-Pester pester#710

Changes:
 - Simply tests if there is a path property, if so uses it for the message formatting. Otherwise, falls back to original method.
 - `-join ', '` was used to provide consistency with current messages, as the default ("', '") has no bracketing quotes.

Functions/Output.ps1

@@ -65,7 +65,11 @@ function Write-PesterStart {
 
         $OFS = $ReportStrings.MessageOfs
 
-        $message = $ReportStrings.StartMessage -f "$($Path)"
+        if ($Path.Path) {
+            $message = $ReportStrings.StartMessage -f "$($Path.Path -join ', ')"
+        } else {
+            $message = $ReportStrings.StartMessage -f "$($Path -join ', ')"
+        }
         if ($PesterState.TestNameFilter) {
            $message += $ReportStrings.FilterMessage -f "$($PesterState.TestNameFilter)"
         }