Support all 1.x versions of datasource-juggler

Modify the loopback-datasource-juggler semver specifier in
peerDependencies and devDependencies from `~1.3.11` to `^1.3.11`.
The goal is to support newer 1.x versions like 1.4.0 or 1.5.x.

/to @ritch or @raymondfeng please review

I am intending to release this change as a patch version 1.8.1. Are you aware of any reason why a minor version 1.9.0 should be published instead?