Improvements, adjustments and organization

[joao10lima]

This issue presents a high level view of the issues we intend to work on next:

Done:

• Ruby plugin doesn't detect version #130
• Python project with pipenv generates broken commands #132
• Incomplete/incorrect remediation instructions #131
• Split general tests by stack #142
• Standardize warning messages  #141
• Delete old unit tests / Check coverage for General tests #146
• Add YAML stack #129
• Python pipelines can evaluate dependencies code #133
• Keep track of the latest versions of runtimes by stack  #152

TODO:

• Revise first stacks implementations #147
• Groom generated YAMLs #135
• Test the full flow of CI #153

Blocked:

• Drop Node < 15 support #148
• https://github.com/pipelinit/landing-page/issues/40