1.4.0 - SQLCipherStore Hardening

1.4.0 - SQLCipherStore Hardening

As this library sees more use, we've identified several potential sources of error that we'd like to proactively prevent. First, we want updates to be the only mechanism through which state updates are published to observers. To enforce this, we've hidden both states and errors publishers concrete implementations, and made both the current state and error values derive their values from their associated publishers, rather than the converse.

Full Changelog: 1.3.0...1.4.0