language: elixir
elixir:
  - 1.3.4
  - 1.4.5
  - 1.5.0
  - 1.5.1
otp_release:
  - 18.2.1 
  - 18.3
  - 19.2
  - 19.3
  - 20.0

language: elixir
elixir:
  - 1.3.4
  - 1.4.5
  - 1.5.0
  - 1.5.1
otp_release:
  - 18.2.1
  - 18.3
  - 19.2
  - 19.3
  - 20.0
matrix:
  exclude:
    - elixir: 1.3.4
      otp_release: 20.0

Exclude elixir 1.3.4 on otp 20.0
Exclude elixir 1.3.4 on otp 20.0