adding version checks for backends

[scarrazza]

Implements a simple version check for backends, including the mirroring with setup.py.

[codecov]

Codecov Report

Merging #412 (349dcb0) into bkdocs (bf43f1e) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            bkdocs      #412   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files           79        79           
  Lines        11398     11399    +1     
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+ Hits         11398     11399    +1     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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Impacted Files	Coverage Δ
src/qibo/backends/__init__.py	100.00% <100.00%> (ø)

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[stavros11]

Thanks, the check looks good but only checks the tensorflow version. If I understood correctly your comment here we would also like to check that the qibotf version is compatible with the qibo version.

[stavros11]

We could also move this to config.py.

[scarrazza]

Any special reason to move that to config.py?

[stavros11]

No, other than that we define all other "constants" used throughout the qibo code there. I don't have any strong preference on what is the right position for TF_MIN_VERSION though.

[scarrazza]

I believe the only strong requirement we have now is the tf version, given that for qibotf we don't have any specific API that requires locking their version.

[stavros11]

I believe the only strong requirement we have now is the tf version, given that for qibotf we don't have any specific API that requires locking their version.

I agree with this, so I guess this should be fine to merge now and if at some point we create some API inconsistency between qibo and qibotf we can use the same template the check the corresponding versions.

[scarrazza]

@stavros11, yes, thanks, I agree.