add license checker (#6715)

* add license checker
* add command to package.json
* Merge branch 'master' into licne

Author: normanrz

package.json

@@ -121,6 +121,7 @@
     "format-frontend": "node_modules/.bin/prettier --write --config .prettierrc \"frontend/javascripts/**/*.ts\" \"frontend/javascripts/**/*.tsx\" \"tools/**/*.js\"",
     "format-backend": "sbt \";scalafmt; util/scalafmt; webknossosTracingstore/scalafmt; webknossosDatastore/scalafmt\"",
     "lint-backend": "sbt \";scapegoat\"",
+    "licenses-backend": "sbt dumpLicenseReport",
     "am-i-pretty": "node_modules/.bin/prettier --list-different --config .prettierrc \"frontend/javascripts/**/*.ts\" \"frontend/javascripts/**/*.tsx\" \"tools/**/*.js\"",
     "docs": "node_modules/.bin/documentation build --shallow frontend/javascripts/oxalis/api/api_loader.ts frontend/javascripts/oxalis/api/api_latest.ts --github --project-name \"webKnossos Frontend API\" --format html --output public/docs/frontend-api",
     "refresh-schema": "./tools/postgres/refresh_schema.sh && rm -f target/scala-2.12/src_managed/schema/com/scalableminds/webknossos/schema/Tables.scala",

project/license.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.typesafe.sbt" % "sbt-license-report" % "1.2.0")