Adapt to KerasTuner 1.1.0

[haifeng-jin]

Which issue(s) does this Pull Request fix?

resolves #000

Details of the Pull Request

[codecov]

Codecov Report

Merging #1640 (047a999) into master (5037540) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master     #1640   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           51        51           
  Lines         3350      3353    +3     
=========================================
+ Hits          3350      3353    +3     

Impacted Files	Coverage Δ
autokeras/auto_model.py	100.00% <100.00%> (ø)
autokeras/engine/tuner.py	100.00% <100.00%> (ø)
autokeras/tuners/greedy.py	100.00% <100.00%> (ø)

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