flogo list command not reporting connection type contributions

[ppaidi]

Result of flogo list command doesn't include connection type (flogo:connection) contributions.

Steps to reproduce:

1. Create a flogo app using any valid application json - flogo create -f app.json
2. Install a connection type contribution, run - flogo install github.com/project-flogo/messaging-contrib/pulsar/connection
3. Run flogo list - result doesn't include the installed connection contribution

Expected behaviour:

flogo list command should also return the list of installed connection type contributions