Add missing .npmignore, bump version to 0.7.2 (swiftwasm#85)

Merge pull request swiftwasm#84 from swiftwasm/npm-publish

Automatically publish to npm

Merge pull request swiftwasm#78 from swiftwasm/readme-5.3-snapshot

Specify correct SwiftWasm snapshot in `README.md`

Bump 0.6.0

Bump 0.5.0

Bump 0.4.0

Bump 0.3.0

Bump 0.2.0

Update package.json