Rename probability to analytic_probability

[antalszava]

This change follows-up the change in the structure of QubitDevice:
PennyLaneAI/pennylane#573

[codecov]

Codecov Report

Merging #24 into master will increase coverage by 0.62%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #24      +/-   ##
==========================================
+ Coverage   98.70%   99.33%   +0.62%     
==========================================
  Files           6        6              
  Lines         155      151       -4     
==========================================
- Hits          153      150       -3     
+ Misses          2        1       -1     

Impacted Files	Coverage Δ
pennylane_cirq/_version.py	100.00% <100.00%> (ø)
pennylane_cirq/cirq_device.py	100.00% <100.00%> (ø)
pennylane_cirq/simulator_device.py	100.00% <100.00%> (+1.61%)	⬆️

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[thisac]

Looks good! 💯

[josh146]

Thanks @antalszava! I'm curious about the missing 4 lines of coverage - I'm assuming this is because analytic_probability() is not being called in the test suite?

[antalszava]

Thanks! It was the self._state is None case, added a small test for coverage on that! 😊

Other than that implicit calls coming from for example expval in the analytic=True case made up for the other parts in coverage for now.