chore(*): Upgrade Several Crates

[jolhoeft]

Addresses #395

[GitCop]

Thanks for contributing! Unfortunately, I'm here to tell you there were style issues with your Pull Request:

• Commit: 2d64d31

• Commits must be in the following format: %{type}(%{scope}): %{description}

• Commit: 7eff6bc

• Commits must be in the following format: %{type}(%{scope}): %{description}

Guidelines are available at https://github.com/nickel-org/nickel.rs/blob/master/contributing.md

---

This message was auto-generated by https://gitcop.com

[jolhoeft]

The Travis failures appear to be due to #399

[GitCop]

Thanks for contributing! Unfortunately, I'm here to tell you there were style issues with your Pull Request:

• Commit: 2d64d31

• Commits must be in the following format: %{type}(%{scope}): %{description}

• Commit: 7eff6bc

• Commits must be in the following format: %{type}(%{scope}): %{description}

• Commit: b517381

• Commits must be in the following format: %{type}(%{scope}): %{description}

Guidelines are available at https://github.com/nickel-org/nickel.rs/blob/master/contributing.md

---

This message was auto-generated by https://gitcop.com

[jolhoeft]

I've created a new pull request that is a bit cleaner, #401. Closing this in favor of that one.