Change fix version to 1.2.0

I need to rev some of the versions of the libraries they depend on:

1. retrofit → 2.5.0 → 2.9.0

2. retrofit converter-jackson → 2.1.0 → 2.9.0

3. okhttp3 → 3.3.1 → 4.9.1

   1. A major version change, but the IdP no longer supplies this, so no clash is expected.

4. okhttp3 logging interceptor → 3.3.1 → 4.9.1

5. They have also updated jackson-core to 2.12.4. We use the IdP 4.1.2 supplied v2.12.2. Apache seems to follow semantic versioning or close to it (https://github.com/FasterXML/jackson/wiki/Jackson-Releases#general ). So these should be compatible and I will not attempt to override that supplied by the IdP.

Version 1.1.3 of the SDK has since been released. I look to upgrade to that.

Updated.