Numerous updates

[greglandrum]

Some of the changes here:

• Use rdkit master instead of a particular release. We should be sure to change this before merging to master
• Switch the linux and mac builds to boost 1.63
• Pin the conda version in an attempt to avoid their new builds

I've tested the full thing on the Mac and on CentOS6 with py36 (py35 seems to always be the same) and py27. Most of this has also been tested on windows, but I will confirm that again.

I have not updated the other pieces, the cartridge build in particular, but that should also be done.

[greglandrum]

@rvianello : I think this is now mergeable as is. I've tested the rdkit-postgresql95 recipe on the mac and it looks fine. Do we still need to support building older versions?

Once this is merged onto development, I think we should consider pushing it to master as well.

[rvianello]

@greglandrum thanks for the updates, and sorry for the slow feedback. the rdkit-postgresql95 recipe worked fine with the upstream 'postgresql' in my tests too, and I also agree that there should be little need for building the cartridge for the older versions (once the master is updated we could maybe consider removing some of these recipes that are no longer useful).