Wrap table creation to guard clause

db/migrate/20200825084819_create_security_findings_table.rb

@@ -8,13 +8,15 @@ class CreateSecurityFindingsTable < ActiveRecord::Migration[6.0]
   disable_ddl_transaction!
 
   def up
-    create_table :security_findings, if_not_exists: true do |t|
+    unless table_exists?(:security_findings)
+      create_table :security_findings do |t|
         t.references :scan, null: false
         t.references :scanner, null: false
         t.integer :severity, limit: 2, index: true, null: false
         t.integer :confidence, limit: 2, index: true, null: false
         t.text :project_fingerprint, index: true, null: false
       end
+    end
 
     add_text_limit :security_findings, :project_fingerprint, 40
   end