fix(types): add skipLibCheck bc conflicting cypress- and jest-types

we now trust .d.ts-files blindly, mostly because the mocha shipped by cypress
conflicts with jest otherwise. an alternative approach would be to whitelist
@types per `"types": ["jest", "graphql", ...],`, but as this introduces a
high chance of forgetting to add new libs here, we stick with skipLibCheck.

-------------------

to learn more, you might want to look here:
cypress-io/cypress#1087

tsconfig.json

@@ -24,6 +24,7 @@
     "experimentalDecorators": true,
     "emitDecoratorMetadata": true,
     "baseUrl": "./",
+    "skipLibCheck": true,
     "paths": {
       "@dcos/http-service": ["src/typings/dcos__http-service"],
       "*": ["*", "packages/*", "src/typings/*"],