Change default cache directory

[stevenvachon]

• Operating System: macOS 10.14.3
• Node Version: 10.15.2
• NPM Version: 6.4.1
• webpack Version: 4.29.5
• cache-loader Version: 2.0.1

Feature Proposal

Instead of ./cache-loader, it should be ./node_modules/.cache/cache-loader

Feature Use Case

Consistent with other loaders and to avoid a specific gitignore.

[alexander-akait]

Yep, feel free to send a PR