Picking latest solidity version from the given interval

[nanspro]

Fixes #12

[muellerberndt]

@cleanunicorn apparently something is wrong with the CI setup?

[nanspro]

Yeah i just updated the PR to fix lint errors but it is still showing the same

[cleanunicorn]

@nanspro I just tested it and it doesn't If you specify an upper and lower Solidity version.

I think these should be supported but also any others that are valid in Solidity.

I've added some examples it should work with:

pragma solidity >=0.4.24; // Should be latest
pragma solidity >0.4.24; // Should be latest
pragma solidity >0.4.20 <0.5.0; // Should be 0.4.25
pragma solidity >=0.4.20 <=0.5.0; // Should be 0.5.0
pragma solidity >0.4.20 <=0.5.0; // Should be 0.5.0
pragma solidity <0.5.0; // Should be 0.4.25
pragma solidity <=0.5.0; // Should be 0.5.0

[nanspro]

@cleanunicorn ahh yes there was a small mistake. fixed and tested it on all the above examples