Add compression to release downloads

Changelog for v0.0.1-rc4:

• PR #5 add compression to binaries by @rgee0

Commits
5109a6f add compression to binaries by @rgee0
9d3d9e5 Update README.md by @alexellis
65f621e Clarify write flag by @alexellis
0c5f2ff Update README.md by @alexellis
fe7b7a5 Update README.md by @alexellis
af5b02f Update README.md by @alexellis

Changes: v0.0.1-rc3...v0.0.1-rc4

Generated by Derek