Update package.json to use dynamic tags

package.json

@@ -14,8 +14,8 @@
     "test": "jest",
     "test:debug": "yarn cross-env NODE_OPTIONS=\"--no-deprecation\" DEBUG=\"esdb:*\" DEBUG_DEPTH=6 DEBUG_COLORS=\"true\" jest --verbose --run-in-band",
     "test:flake": "jest --testSequencer=./src/__test__/utils/FlakeFinder.js",
-    "21.10": "yarn cross-env EVENTSTORE_IMAGE=github:21.10.1-focal jest",
-    "20.10": "yarn cross-env EVENTSTORE_IMAGE=github:20.10.5-focal jest",
+    "latest": "yarn cross-env EVENTSTORE_IMAGE=github:latest jest",
+    "previous-lts": "yarn cross-env EVENTSTORE_IMAGE=github:previous-lts jest",
     "generate": "run-s generate:*",
     "generate:sed-append": "shx sed -i \"s/int64 ([A-z_]*) = ([0-9]*) \\[deprecated = true\\];/int64 \\$1 = \\$2 [deprecated = true, jstype = JS_STRING];/g\" ./protos/*",
     "generate:sed-insert": "shx sed -i \"s/int64 ([A-z_]*) = ([0-9]*);/int64 \\$1 = \\$2 [jstype = JS_STRING];/g\" ./protos/*",