[ru] Update basics/testing.md to 1.2.0 (#2004)
[ru] Update basics/testing.md to 1.2.0 (#2004)

- Newline all the sentences to correspond to English source
doomspork/elixir-school,doomspork/elixir_school,doomspork/elixir-school,doomspork/elixir-school,nscyclone/elixir-school,nscyclone/elixir-school,nscyclone/elixir-school,doomspork/elixir_school,doomspork/elixir_school,nscyclone/elixir-school