Correcting random_state passed to pipelines

[angela97lin]

There's a bug where random_state (and n_jobs) were not correctly passed to the PipelineBase constructor; fixing and adding test cases here.

[codecov]

Codecov Report

Merging #204 into master will increase coverage by 0.04%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #204      +/-   ##
==========================================
+ Coverage   96.73%   96.78%   +0.04%     
==========================================
  Files          91       91              
  Lines        2298     2333      +35     
==========================================
+ Hits         2223     2258      +35     
  Misses         75       75

Impacted Files	Coverage Δ
evalml/pipelines/regression/linear_regression.py	100% <ø> (ø)	⬆️
evalml/pipelines/classification/random_forest.py	100% <ø> (ø)	⬆️
...ml/pipelines/classification/logistic_regression.py	100% <ø> (ø)	⬆️
evalml/pipelines/classification/xgboost.py	100% <ø> (ø)	⬆️
evalml/pipelines/regression/random_forest.py	100% <ø> (ø)	⬆️
...l/tests/pipeline_tests/test_logistic_regression.py	100% <100%> (ø)	⬆️
...lml/tests/pipeline_tests/test_linear_regression.py	100% <100%> (ø)	⬆️
evalml/tests/pipeline_tests/test_xgboost.py	100% <100%> (ø)	⬆️
evalml/tests/pipeline_tests/test_rf.py	100% <100%> (ø)	⬆️
evalml/pipelines/pipeline_base.py	97.05% <100%> (ø)	⬆️
... and 2 more

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[jeremyliweishih]

LGTM maybe wait on @kmax12 thoughts on the default values.

[kmax12]

Good catch. LGTM