Update PATH variable without duplicating entries

[cosmojg]

Since common.sh is called every time that JuNest is run, the current implementation ends up cluttering the PATH variable with duplicate entries, making it far more difficult for end users to manage their PATH variables themselves. This commit solves that problem by prepending necessary paths with a function that deletes them if they are already present, effectively promoting them rather than duplicating them.

[cosmojg]

To clarify, this is what I see with the existing implementation:

cosmo@junest:~$ echo $PATH
/usr/bin:/bin:/usr/local/bin:/usr/sbin:/sbin:/home/cosmo/.local/bin:/home/cosmo/bin:/home/cosmo/.local/bin:/home/cosmo/.local/share/junest/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/cosmo/.junest/usr/bin_wrappers:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl

And this is what I see after applying my commit:

cosmo@junest:~$ echo $PATH
/usr/bin:/bin:/usr/local/bin:/usr/sbin:/sbin:/home/cosmo/.local/bin:/home/cosmo/bin:/home/cosmo/.local/share/junest/bin:/usr/local/sbin:/usr/games:/usr/local/games:/snap/bin:/home/cosmo/.junest/usr/bin_wrappers:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl

[cosmojg]

@fsquillace Not sure why the build is failing. Do I need to provide Docker credentials somehow?

[fsquillace]

Thanks @cosmojg this should be solved given that PATH will not be affected when accessing to JuNest with this change: https://github.com/fsquillace/junest/commit/9b00c5c4c51c513b09ae32b97a0fbd8ca8590d45

[cosmojg]

Ooh, that definitely seems like the better way to do it since it avoids the need to add new functions and potentially introduce new bugs.

As always, thank you for all your hard work on maintaining JuNest!