Improve resource handling using try-with-resources.

...ain/java/org/torproject/onionoo/docs/BandwidthStatus.java

src/main/java/org/torproject/onionoo/docs/ClientsStatus.java

src/main/java/org/torproject/onionoo/docs/DocumentStore.java

src/main/java/org/torproject/onionoo/docs/UptimeStatus.java

src/main/java/org/torproject/onionoo/docs/WeightsStatus.java

...n/java/org/torproject/onionoo/server/ResourceServlet.java

.../org/torproject/onionoo/updater/DescriptorDownloader.java

.../java/org/torproject/onionoo/updater/DescriptorQueue.java

...in/java/org/torproject/onionoo/updater/LookupService.java

...ava/org/torproject/onionoo/updater/LookupServiceTest.java