Quirks of the travis build

[tjduigna]

Describe the bug
This is just a minor issue with the way the .travis.yml builds exatomic. When mimicking the installation, the command to pip install -e exa/ requires a pip install of the following packages:

Installing collected packages: scipy, networkx, kiwisolver, cycler, matplotlib, seaborn, exa
  Running setup.py develop for exa

To Reproduce
Steps to reproduce the behavior:

Run the commands in the .travis.yml starting from:

exatomic/.travis.yml

Line 34 in 815b921

- conda create -n test python=$PYTHONVER

to

exatomic/.travis.yml

Line 44 in 815b921

- pip install -e exa/

Expected behavior
I expected there to be no additional dependencies for pip to install when installing the git clone of exa.
We already enumerate explicitly the packages needed to cover the exa/tomic stack in the .travis.yml file anyway, so perhaps we should leverage conda to install the above dependencies not already picked up.

Desktop (please complete the following information):

• OS: WSL (Ubuntu 14.04)
• Browser: Chrome 71.0.3578.98
• Version: discovered while on Modification to how documentation is constructed #135

Additional context
Thought it may be a suitable issue for exa instead. But since exa/tomic are tightly coupled, it makes sense that we directly git clone exa during the exatomic build. Therefore it may only pertain to the exatomic build directly.

[avmarchenko]

This is a good catch. Like you write, one possible approach might be to modify the requirements.txt in exa. My gut reaction is that that is the most appropriate approach - a fix it at the source type approach. Waiting for others to weigh in.

[tjduigna]

May be a non-issue 😃 having trouble reproducing, it may have just been a conda installation fail. I will close this if I can't reproduce it.

[herbertludowieg]

Just want to bump this.
Is it still an issue?

[tjduigna]

Closing in favor of #231