Fixes param bugs, formatting fixes, audit fixes

[divmgl]

• Fixed issues related to using use after param param stops working if followed by use #506 populate ctx.params before running any matched middleware #490
• Fixed issues with params not populating in nested routers
• Fixed issues with params not populating in prefixed routers Issue accessing route params with prefix  #422
• Added eslint
• Added .eslintrc with JavaScript standard style guide
• Formatted entire package
• Fixed high-risk dependency vulnerabilities Fix security vulnerabilities from NPM audit #504

[divmgl]

Thanks to @smkoyan for the original PR

[jmitchell38488]

@divmgl it looks as though the commits have removed the semi-colons in layer.js and router.js, as well as reformatting the file to use less spaces.

Is this inline with the current coding standards?