Adding homepage and bugs links to package.json

Note, this still throws warnings on http://package-json-validator.com/ saying that "latest" isnt semver-ey:
```json
{
  "valid": false,
  "errors": [
    "Invalid version range for dependency eslint-tester: latest"
  ],
  "warnings": [
    "Missing recommended field: contributors"
  ],
  "recommendations": [
    "Missing optional field: engines"
  ]
}
```
Add env flag to cli options summary (fixes #752)
readme: npm i -> npm install

Although `npm i` is shorter to type, having it in the readme adds some unnecessary complexity. I had to stop and think to figure out what the command actually did. As all other projects I've come across uses `npm install`, I think it's better to follow an accepted convention and show the longer command.

For people that copy and pastes it won't make a difference, and people that type it out can still use the sort version.
Merge pull request #753 from btmills/fix-752

Add env flag to cli options summary (fixes #752)
Merge pull request #754 from LinusU/patch-1

readme: npm i -> npm install
Breaking: implement eslint-env and remove jshint/jslint environment comment support (fixes #759)
Rule block-scoped-var works correct with object properties (fixes #755)
Merge pull request #763 from roadhump/issue_759_pr

Added env configuration per file (fixed #759)
Lint tests on build (fixes #764)
Merge pull request #739 from pdehaan/patch-4

Adding homepage and bugs links to package.json
Fix: Cleanup package.json
Merge pull request #766 from roadhump/issue_764

Lint tests on build using their .eslintrc file (fixes #764)
Merge pull request #757 from roadhump/issue_755

fixes #755: block-scoped-var with object properties
Add options for rule 'no-unused-vars' to check all arguments in functions (fixes #728)
update to latest Optionator

allows for multiple flags to array,
update env flag documentation to reflect this

closes #773
Merge pull request #774 from gkz/optionator-update

Update to latest Optionator
Merge pull request #771 from roadhump/issue_728

Add options for 'no-unused-vars' to check all arguments in functions (fixes #728)
Add global cli flag (ref #692)

Adds a --global cli flag to define global variables. To define
multiple variables, either separate them using commas, or use the
flag multiple times. By default, all variables are read-only, but
appending `:true` to the name will mark it as writable.

Example:

    eslint --global require,exports:true file.js
    eslint --global require --global exports:true file.js