Updated README, added os & db version tests, updated test library for 10.13

tests/Test-10.13.6.photoslibrary/resources/recovery/Info.plist

@@ -9,7 +9,7 @@
 	<key>HistoricalMarker</key>
 	<dict>
 		<key>LastHistoryRowId</key>
-		<integer>551</integer>
+		<integer>615</integer>
 		<key>LibraryBuildTag</key>
 		<string>BEA5F0E8-BA6B-4462-8F73-3E53BBE4C943</string>
 		<key>LibrarySchemaVersion</key>
@@ -24,7 +24,7 @@
 	<key>SnapshotCompletedDate</key>
 	<date>2019-07-26T20:15:17Z</date>
 	<key>SnapshotLastValidated</key>
-	<date>2019-07-26T20:15:17Z</date>
+	<date>2019-07-27T12:01:15Z</date>
 	<key>SnapshotTables</key>
 	<dict/>
 </dict>