Add dependencies for testing

[notZaki]

I was checking some old code and the tests kept failing. This PR should hopefully make the Travis tests pass.

---

Changes:

• Add dependencies to Project.toml
  • This was done somewhat manually by navigating to the project directory and then:

   Julia>]activate .
   Julia>]add <dependencyNameOneByOne>
  

  • Alternatively, I think ]resolve would've done the same thing
• Travis uses the installed python version and so matplotlib needs to be installed for it. There might be a way to force it to use the Conda.jl, but I didn't have time to figure it out.
• I (re?)commented that script section in .travis.yml to enable the default test script. I think the default script is better at handling different Julia versions, but I also don't know if there was a reason why it was overridden in the first place.

[davidssmith]

Thank you thank you thank you!

I've tried a few times in my spare time to update the code, and I'm just too far removed from the current Julia situation to fix it properly.