pkg/units: fix size_test.go compilation

Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com>
Merge pull request #9751 from unclejack/revert_9233

Fix pkg/units compilation of size_test
bump Go to 1.4

Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com>
Reinstall standard library with netgo

Fixes #9449

Signed-off-by: Alexander Morozov <lk4d4@docker.com>