ultragraph-v0.5.0

Other

• Switched to shorter version numbers in Cargo.toml
• Fixed linter issue
• Formatted entire code base with rustfmt.
• Separate ultragraph type implementation imn multiple files.
• Added convince constructor to error
• Fixed broke test for node remove error.
• Added missing none checks to graph_root_tests.rs
• Fixed fallibility in shortest path.
• Separate ultragraph tests into multiple files.
• Renamed example code files to prevent output file name collision.
• Updated copyright in all source and bash script files.
• Updated copyright in all licence files.