Adds npm support and eslint

[alulsh]

• Initial package.json file
• Adds eslint for code linting, with eslintrc config file
• Modifies .gitignore to ignore npm-debug.log files

Right now eslint is checking all JavaScript files (*.js) in the main directory of the repo - if we move to a dedicated js or app directory then we will need to update the command.

/cc @NealHumphrey