feat(ci): add some unit and integration tests

[jakedoublev]

This PR introduces the following tests:

1. file system store encrypts files
2. all stores can get/set/delete
3. platform package behaves as expected (further research needed for Windows platform interface)
4. integration tests for a variety of profile CRUD scenarios against a profiler with a keyring store

It also:

1. fixes a bug where the Set/Get from an in-memory store double-marshaled the profile bytes.
2. adds gnome-keyring as an ubuntu dependency for the zalando/go-keyring module to succeed