The `reflect-metadata` package should be a peer dependency.

[jloveridge]

I have encountered issues when multiple dependencies of a project depend on the reflect-metadata package. When this occurs I have seen tsc fail to transpile the project source. This has, in my experience, been avoidable by listing reflect-metadata in peerDependencies instead of dependencies and allowing the project itself to install one version of the reflect-metadata package.

[coveralls]

Coverage remained the same at 100.0% when pulling 7c4dbbf1894b1bb8949e83ec00dbe0476e156ea5 on gradecam:feature/peer-reflect into 109f38a9ce4b65710ea42d3eb7e0760b36aa4e85 on bitrinjani:master.