Fixed typo in release notes

Release 0.59a2 Refs #942, #1421, #1423, #1431, #1443, #1446, #1449

Release 0.59a1 Refs #1425

Release 0.59a0 Refs #1404, #1405, #1416, #1420, #1422

Release 0.58.1 Refs #1231, #1396

Release 0.58 Refs #1365, #1371, #1377, #1384, #1387, #1388, #1389, #1394

Release 0.58a1 Refs #1365, #1377

Release 0.58a0 Refs #1371

Release 0.57.1 Refs #1364, #1367

Release 0.57 Refs #263, #615, #619, #1238, #1257, #1305, #1308, #1320, #1332, #1337, #1349, #1353, #1359, #1360

Release 0.56.1 Refs #1360

Release 0.57a1 Refs #1319, #1320, #1331, #1337, #1338, #1341

Release 0.57a0 Refs #1281, #1282, #1289, #1290, #1308, #1313, #1314, #1321, #1323, #1325, #1330, #1332, #1335

Release 0.56 Refs #1005, #1031, #1141, #1229, #1236, #1239, #1246, #1247, #1252, #1266, #1276, #1278

Release 0.55 Refs #1205, #1207, #1214, #1221, #1226, #1227, #1232, #1235

Release 0.54.1 Refs #1214

Removed a rogue full-stop

Better tool for extracting issue numbers

Release 0.53 Refs #1132, #1135, #1133, #1138, #1137

Release 0.52.5 Refs #1134