Fix analyses not showing on logout -> login

[rwblair]

Also clears analyses on logout. Also fixes a problem with checking the truthiness of isGAuth in the authstore.

[codecov-io]

Codecov Report

Merging #667 into master will decrease coverage by 3.98%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master    #667      +/-   ##
=========================================
- Coverage   85.78%   81.8%   -3.99%     
=========================================
  Files          66      57       -9     
  Lines        2913    2231     -682     
=========================================
- Hits         2499    1825     -674     
+ Misses        414     406       -8

Impacted Files	Coverage Δ
neuroscout/tests/request_utils.py
neuroscout/tests/api/test_dataset.py
neuroscout/tests/api/test_user.py
neuroscout/tests/api/test_predictor.py
neuroscout/tests/test_views.py
neuroscout/tests/api/test_analyses.py
neuroscout/tests/test_models.py
neuroscout/tests/conftest.py
neuroscout/tests/api/test_run_task.py

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[adelavega]

Fixes #666