psycopg2 needs to change to psycopg2-binary to avoid adding build instructions

[Ed McDonagh]

From the next version of psycopg2, the binary version will only be available from pip as psycopg2-binary. They want you to build it each time against the various libraries - for our purposes the binary will be sufficient!

[Ed McDonagh]

I tested installing psycopg2-binary on a linux system with psycopg2 installed, no issues.

I then uninstalled psycopg2, which seemed to break things. However... uninstalling psycopg2-binary and reinstalling it again fixed it.

For existing users installing the next version, psycopg2-binary will install alongside psycopg2, and nothing should change (I think the binary package will be ignored).

New users installing the next version will get psycopg2-binary only and all should be well.

[Ed McDonagh]

So, that was a waste of effort. The database install instructions already refer to the binary version. We could add it to the default install (only 2.7 MB if they don't end up using it). I think that is what I would do if starting now, but not sure it is worth changing?

Brief opinion anyone?

[Ed McDonagh]

May as well leave as is for now.