Support for EPCI generation, move to piscina lib for queue and fix ES6 issues

• Merge pull request #128 from etalab/merge-epci-geojson-v2 da996d8
• Update to support merging EPCI data b62c27d
• EPCI support 8f325eb
• Fix issues in import e91de9d
• Continue piscina try 284d294
• Continue piscina try 8631b7c
• Continue piscina try e51e608
• Continue changes to use piscina f8fbc26
• Try psicina to solve worker-farm not compatible with ES modules 720e18b
• Fix issues d603543
• Fix issues 7a00fc3
• Fix es6 import 7c64b8b
• Update Node version in README fa02bb5
• Merge pull request #127 from etalab/es6-migration 45ea5d1
• Change references from github repos to npm packages in package.json bfbd382
• Change to disable some false positive in eslint fc05b12
• Change yarn.lock f58a0e9
• Fix to make circleci works ed85d3a
• Fix to make circleci works d0dde51
• Fix yarn.lock to make circleci works 105e668
• Fix package.json and yarn.lock to make circleci works 43badc5
• Fix yarn.lock 8e5ae84
• Fix yarn.lock 0415b79
• Add circleci integration 3e251a0
• Continue fixing es6 00e2361
• Continue upgrading code to es6 3f71e3c
• Intermediate step 0926b17
• Add extras directory to support cadastre loading 4b62904
• Update README - add warning for EMS data c0d9760
• Update README.md 2291cdb

v0.17.0...v0.18.0