Apply more pinning to jupyter in IT. (#573)
Apply more pinning to jupyter in IT. (#573)

I ran into the following in `test_jupyter_appnope_env_markers` this am`:
```
Could not satisfy all requirements for prompt-toolkit<2.0.0,>=1.0.4:
    prompt-toolkit<2.0.0,>=1.0.4(from: ipython<6), prompt-toolkit<2.1.0,>=2.0.0(from: jupyter==1.0.0->jupyter-console)
```
pantsbuild/pex,jsirois/pex,jsirois/pex,pantsbuild/pex