Bumps minor versions of dependencies

[bruno-azenha]

{:floki, "~> 0.32.0"},
{:tesla, "~> 1.4"},
{:html_entities, "~> 0.5", optional: true},
{:mogrify, "~> 0.9.1", optional: true},
{:tempfile, "~> 0.1.0", optional: true},
{:excoveralls, "~> 0.14", only: :test},
{:ex_doc, "~> 0.28", only: :dev},