Missing steps in Readme

[rashmihunt]

Here are the steps that are missing in order to run this sample successfully.

1. Add step to to checkout 'soap' branch specifically - 'git clone https://github.com/strongloop/loopback-example-connector.git -b soap'
2. Before running 'node stock-ws.js' user needs to run 'npm install' otherwise user will see 'Cannot find module loopback' error. Need to add this step in readme.
   3)Also add a step to run 'npm install loopback-explorer' before running 'node weather-rest.js' Otherwise user will see 'raiseUrlNotFoundError' when they invoke the explorer. Missing 'loopback-explorer` dependency in package.json?

[superkhau]

Would you like to a submit a PR that targets the soap branch?