remove third-party/

Summary:
Remove the third-party/ directory and no longer rely on copies of dependencies
in the repo. When needed, fetch dependencies normally. This can usually be
accomplished via `pip install -r requirements.txt` or `pip install -r
requirements-dev.txt`.

Even though `peru.yaml` is gone, `.peru/` is still in `.gitignore`, because the
tests check for untracked files and will detect `.peru/` as an error.

Test Plan: Successfully ran tests locally and via Travis CI.

Reviewers: jacko

Reviewed By: jacko

Differential Revision: https://phabricator.buildinspace.com/D145
packaging for Debian and Ubuntu

Summary:
Add Debian packaging metadata and a script to generate a basic source package
that can be uploaded to a Launchpad PPA.

Reviewers: jacko

Reviewed By: jacko

Differential Revision: https://phabricator.buildinspace.com/D133
bump version to 0.1.2

Summary:
Important changes in this release:
- fix curl plugin's quote handling (D144)
- support user-defined plugins (D141)

Reviewers: sean

Reviewed By: sean

Differential Revision: https://phabricator.buildinspace.com/D147