Rewrite TestBuildSixtySteps to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestAddSingleFileToRoot to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestAddSingleFileToWorkdir to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestAddSingleFileToExistDir to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestAddSingleFileToNonExistDir to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestBuildAddDirContentToRoot to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestBuildAddDirContentToExistDir to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestBuildAddEtcToRoot to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Rewrite TestBuildAddWholeDirToRoot to not use fixtures

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Merge pull request #8168 from LK4D4/rewrite_fixture_tests

Rewrite some tests to not use fixtures