Use the https not git@ protocol to get the RMG-database in .travis.yml

The builds got this far then stopped for 10 minutes and were killed:
$ git clone git@github.com:GreenGroup/RMG-database.git
Cloning into 'RMG-database'...
The authenticity of host 'github.com (192.30.252.128)' can't be established.
RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48.
Are you sure you want to continue connecting (yes/no)?

Hopefully the https version can continue without the RSA fingerprint check...
Use system site_packages (and numpy/scipy) in travis config.

Currently it spends thousands of lines of log file (and quite some time)
compiling scipy for each build. The Ubuntu apt-get install of python-scipy
should save this, but you need to enable the system site packages (instead
of the isolated virtual environment) to use it. [1,2]

Hopefully this (using the system site packages) also fixes the apparent
failure of rdkit: current build failed with:
echo "Checking you have rdkit..."
Checking you have rdkit...
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named rdkit

[1] http://danielnouri.org/notes/2012/11/23/use-apt-get-to-install-python-dependencies-for-travis-ci/
[2] https://github.com/dnouri/nolearn/blob/master/.travis.yml
Simplify travis config: no QM and no Python 2.6

Trying to get the simplest possible configuration working first,
then will add complexity.
Remove redundant parts from Travis config file.

--use-mirrors has been deprecated, and pip install .  likely isn't needed
Try using the apt-get version of matplotlib too, in travis build.

This should speed up and simplify the build, if it works.
Try building RDKit from source during Travis-CI testing

These lines in the build script are based off the RDKit travis config
https://github.com/rdkit/rdkit/blob/master/.travis.yml
But modified to turn on InChI support
Once this is working we can worry about cacheing the finished
build to speed it up.
Travis gets and builds PyDAS and PyDQED

Unlike the instructions for users in our installation guide,
don't have Travis sudo the make install for PyDAS and PyDQED.
'sudo' on Ubuntu makes it discover the wrong python, which then doesn't
have Cython installed, and it all goes wrong. Hopefully this clears it up.
I also split into several lines, to make debugging the Travis log easier.
Trying to get Travis things in the right directories.

 - RMG-database
 - RPyDAS
 - RPyDQED
 - Rrdkit
etc.
should all live alongside, not inside, the RMG-Py directory.
Hopefully this works solves the database problem
Try running eg1 as well as make test in travis testing.
Merge pull request #194 from GreenGroup/travis

Getting Travis-CI builds working