test: Rename connect! to setup!; use ensure

Change connect! to setup!, so that we can use connect! to give us an
empty DB with no tables.

Use ensure where appropriate to ensure that tests after that one can run
even if it fails.

test/paranoia_test.rb

@@ -11,6 +11,10 @@ require File.expand_path(File.dirname(__FILE__) + "/../lib/paranoia")
 
 def connect!
   ActiveRecord::Base.establish_connection :adapter => 'sqlite3', database: ':memory:'
+end
+
+def setup!
+  connect!
   ActiveRecord::Base.connection.execute 'CREATE TABLE parent_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
   ActiveRecord::Base.connection.execute 'CREATE TABLE paranoid_models (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER, deleted_at DATETIME)'
   ActiveRecord::Base.connection.execute 'CREATE TABLE paranoid_model_with_belongs (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER, deleted_at DATETIME, paranoid_model_with_has_one_id INTEGER)'
@@ -36,7 +40,7 @@ class WithDifferentConnection < ActiveRecord::Base
   acts_as_paranoid
 end
 
-connect!
+setup!
 
 class ParanoiaTest < test_framework
   def setup
@@ -602,7 +606,8 @@ class ParanoiaTest < test_framework
     a.destroy!
     a.restore!
     # This test passes if no exception is raised
-    connect! # Reconnect the main connection
+  ensure
+    setup! # Reconnect the main connection
   end
 
   def test_restore_clear_association_cache_if_associations_present