fix(deps): Fix deprecations when compiling

[raksonibs]

Resolves:

ex_doc is missing its version requirement, use ">= 0.0.0" if it should match any version
inch_ex is missing its version requirement, use ">= 0.0.0" if it should match any version
earmark is missing its version requirement, use ">= 0.0.0" if it should match any version
benchfella is missing its version requirement, use ">= 0.0.0" if it should match any version

and

warning: found quoted keyword "coveralls" but the quotes are not required. Note that keywords are always atoms, even when quoted, and quotes should only be used to introduce keywords with foreign characters in them
  mix.exs:17

Thank you for this repo:)

[coveralls]

Coverage remained the same at 100.0% when pulling 8767b82 on raksonibs:fix-deprecations into 27a8bb8 on beatrichartz:master.

[beatrichartz]

Thanks!