Feature/package loader

[emerikaji]

Changes:

• Add the package loader and encoder. Enable the uploading of packages and files to a redis server, with their hash as the key.

Features:

• File struct: Contains its hash, contents, name and length
• Package struct: Contains the package name and a list of its files' hashes
• PackageList struct: Contatins a list of the program packages' hashes
• Loader: From a directory that contains an src, check if all the files in folders belong to the same package, and uploads the Files and Packages to a redis server using their hash. The PackageList is associated to the program's name.
• Encoder: Get the package list associated with a program name, and get all the packages and files back to put them into a directory.

Interface:

• CLI tool has three modes: -help, -load and -save. -load will load the packages from a directory, with the specified program name, with this syntax:

  packageloader -load -path <existing program folder> -name <program name>

• -save will load the packages associated with a program name, and save them to a folder, with this syntax:

  packageloader -save -path <existing program folder> -name <program name>

• -help will show a description of every flag.

Does this change need to mentioned in CHANGELOG.md? Yes

[CLAassistant]

All committers have signed the CLA.

[kenje4090]

For your tests, like in cmd/packageloader/loader. Create a "test_files" folder and put the test files there. Then inside should just have "invalid_program" folder that will contain the invalid program source files, and same with the others