Allow specifying multiple namespaces at once
Version v0.2.0

= new feature

- You can now pass multiple namespaces at once
  (commit 3c1a87f3337a87213aadce6ba204227d9a6f7084)

  $ envchain --set foo TEST_A
  foo.TEST_A: 1
  $ envchain --set bar TEST_B
  bar.TEST_B: 2
  $ envchain foo,bar env | grep TEST_
  TEST_A=1
  TEST_B=2