remove support for in-memory-tests

we haven't supported sqlite in forever

Change-Id: I0e76662d971b24929ca56d36e0344b3d1fa34c14
Reviewed-on: https://gerrit.instructure.com/39820
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jacob Fugal <jacob@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>

config/database.yml.example

@@ -7,12 +7,6 @@ test:
   username: canvas
   timeout: 5000
 
-test-in-memory:
-  adapter: sqlite3
-  encoding: utf8
-  database: ':memory:'
-  pool: 1
-
 development:
   adapter: postgresql
   encoding: utf8

config/initializers/in-memory-test.rb

@@ -1,11 +0,0 @@
-def in_memory_database?
-  Rails.env.test? and
-    ENV["IN_MEMORY_DB"] and
-    Rails::Configuration.new.database_configuration.has_key?('test-in-memory') and
-    Rails::Configuration.new.database_configuration['test-in-memory']['database'] == ':memory:'
-end
-
-if in_memory_database?
-  ActiveRecord::Base.establish_connection(Rails::Configuration.new.database_configuration['test-in-memory'])
-  load "#{Rails.root}/db/schema.rb"
-end