importing laser_polio can take a long time

[jonathanhhb]

time python3 -c "import laser_polio"
python3 -c "import laser_polio"  3.63s user 1.19s system 38% cpu 12.545 total

Almost 13 seconds.
I wonder if this is something we can improve.

[clorton]

  _     ._   __/__   _ _  _  _ _/_   Recorded: 13:10:55  Samples:  3960
 /_//_/// /_\ / //_// / //_'/ //     Duration: 5.272     CPU time: 8.644
/   _/                      v5.0.1

Profile at /Users/christopherlorton/projects/laser-polio/import_time.py:4

5.272 <module>  import_time.py:1
└─ 5.271 <module>  laser_polio/__init__.py:1
   ├─ 4.729 <module>  laser_polio/model.py:1
   │  ├─ 3.716 <module>  laser_core/demographics/__init__.py:1
   │  │     [405 frames hidden]  laser_core, numba, llvmlite
   │  ├─ 0.492 <module>  scipy/stats/__init__.py:1
   │  │     [11 frames hidden]  scipy, importlib
   │  ├─ 0.179 <module>  matplotlib/pyplot.py:1
   │  │     [4 frames hidden]  matplotlib
   │  ├─ 0.174 <module>  pandas/__init__.py:1
   │  │     [4 frames hidden]  pandas
   │  ├─ 0.083 <module>  matplotlib/__init__.py:1
   │  │  └─ 0.055 <module>  matplotlib/rcsetup.py:1
   │  └─ 0.060 <module>  sciris/__init__.py:1
   ├─ 0.295 <module>  laser_polio/distributions.py:1
   │  └─ 0.294 <module>  numpy/__init__.py:1
   │        [9 frames hidden]  numpy
   └─ 0.244 <module>  laser_polio/pars.py:1
      └─ 0.244 <module>  laser_core/__init__.py:1
            [14 frames hidden]  laser_core, numba, llvmlite, ctypes, ...