Update serverless version check

Author: sbstjn

src/plugin.js

@@ -11,8 +11,7 @@ class Plugin {
     this.serverless = serverless
 
     // Check if used serverless version is larger or equal the minimum supported version
-    const unsupportedVersion = cmp(this.serverless.version, MINIMUM_COMPATIBLE_SERVERLESS_VERSION) === -1
-    if (this.serverless.version && unsupportedVersion) {
+    if (this.serverless.version && cmp(this.serverless.version, MINIMUM_COMPATIBLE_SERVERLESS_VERSION) === -1) {
       this.serverless.cli.log(util.format('Skipping `serverless-dynamodb-ttl` plugin. Please update to serverless `%s` or newer', MINIMUM_COMPATIBLE_SERVERLESS_VERSION))
       return
     }