Apply more pinning to jupyter in IT.
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)
```
@@ -879,9 +879,11 @@ def test_platform_specific_egg_resolution_matching():
def test_jupyter_appnope_env_markers():
# NB: jupyter 1.0.0 does not properly pin its dep graph and both ipykernel and ipython support
# python 3 only post 5 and 6 respectively; so we add those deps explictly only to constrain them
- # low such that they support python 2.7 for this test.
+ # low such that they support python 2.7 for this test. We also pin jupyter's unconstrained dep on
+ # jupyter_console low to avoid a conflict with ipython on prompt-toolkit.
res = run_pex_command(['--disable-cache',
'jupyter==1.0.0',
+ 'jupyter_console<5.4',
'ipykernel<5',
'ipython<6',
'-c', 'jupyter',
