Add cargo-generate pacakge installation

[SergioGasquez]

Closes #78

We are currently using x86_64-unknown-linux-musl for x86_64-unknown-linux-gnu arch. If cargo-generate/cargo-generate/pull/602 gets merged I will update the script

[georgik]

Line 413 GENERATE_VERSION is executed always even in case when nothing is requested to install. It adds a dependency on git. Isn't there a simpler way without involving git and bunch of other tools to get latest version? Even fixed version might be better approach.

[SergioGasquez]

Line 413 GENERATE_VERSION is executed always even in case when nothing is requested to install. It adds a dependency on git. Isn't there a simpler way without involving git and bunch of other tools to get latest version? Even fixed version might be better approach.

I encapsulated the git command in an if statement that is only executed when installing cargo-generate, to avoid potential errors from the git command when not installing cargo-generate as we discussed.

I also update the arch being used because they merged cargo-generate/cargo-generate/pull/602 and generated a new release which now has binary packages for x86_64-unknown-linux-gnu.

Finally, I updated the ESP_IDF_VERSION checks to use -z and -n

[georgik]

@SergioGasquez The change looks good. Please could you resolve also the conflict so that we can merge the feature?

[SergioGasquez]

@SergioGasquez The change looks good. Please could you resolve also the conflict so that we can merge the feature?

Conflicts resolved!