Yarn support

Please consider adding yarn support. Some module definitions are incompatible. The project fails installing with yarn:

❯ yarn
yarn install v1.21.1
info No lockfile found.
warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.
[1/5] Validating package.json...
[2/5] Resolving packages...
warning apiconnect-config > apiconnect-project > json-refs > path-loader > superagent@3.8.3: Please note that v5.0.1+ of superagent removes User-Agent header by default, therefore you may need to add it yourself (e.g. GitHub blocks requests without a User-Agent header).  This notice will go away with v5.0.2+ once it is released.
warning apiconnect-config > strong-globalize > g11n-pipeline > swagger-client > @babel/runtime-corejs2 > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning flow-engine > http-auth > node-uuid@1.4.8: Use uuid module instead
warning loopback > strong-remoting > request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning microgateway-datastore > loopback-component-explorer > swagger-ui@2.2.10: No longer maintained, please upgrade to swagger-ui@3.
warning microgateway-datastore > microgateway-util > request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning pug > pug-filters > constantinople > babel-types > babel-runtime > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning eslint > file-entry-cache > flat-cache > circular-json@0.3.3: CircularJSON is in maintenance only, flatted is its successor.
warning supertest > superagent@3.8.3: Please note that v5.0.1+ of superagent removes User-Agent header by default, therefore you may need to add it yourself (e.g. GitHub blocks requests without a User-Agent header).  This notice will go away with v5.0.2+ once it is released.
[3/5] Fetching packages...
error apiconnect-config@2.0.0: The engine "node" is incompatible with this module. Expected version ">=6 <10". Got "13.7.0"
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

If I change node version to >=6 <10 to comply it fails again with a conflicting requirement on another module:

❯ yarn
yarn install v1.22.0
info No lockfile found.
warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.
[1/5] Validating package.json...
[2/5] Resolving packages...
warning apiconnect-config > apiconnect-project > json-refs > path-loader > superagent@3.8.3: Please note that v5.0.1+ of superagent removes User-Agent header by default, therefore you may need to add it yourself (e.g. GitHub blocks requests without a User-Agent header).  This notice will go away with v5.0.2+ once it is released.
warning apiconnect-config > strong-globalize > g11n-pipeline > swagger-client > @babel/runtime-corejs2 > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning flow-engine > http-auth > node-uuid@1.4.8: Use uuid module instead
warning loopback > strong-remoting > request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning microgateway-datastore > microgateway-util > request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning microgateway-datastore > loopback-component-explorer > swagger-ui@2.2.10: No longer maintained, please upgrade to swagger-ui@3.
warning pug > pug-code-gen > constantinople > babel-types > babel-runtime > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
warning eslint > file-entry-cache > flat-cache > circular-json@0.3.3: CircularJSON is in maintenance only, flatted is its successor.
warning supertest > superagent@3.8.3: Please note that v5.0.1+ of superagent removes User-Agent header by default, therefore you may need to add it yourself (e.g. GitHub blocks requests without a User-Agent header).  This notice will go away with v5.0.2+ once it is released.
[3/5] Fetching packages...
info fsevents@1.2.11: The platform "linux" is incompatible with this module.
info "fsevents@1.2.11" is an optional dependency and failed compatibility check. Excluding it from installation.
error mkdirp@1.0.3: The engine "node" is incompatible with this module. Expected version ">=10". Got "9.11.2"
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.