Update TemperatureFormatter.java

Fix +0 temperature
Merge pull request #2 from Litemn/master

Update TemperatureFormatter.java
No error 500 for nonexistent cities

Added default behavior for trying to get weather of invalid
(nonexistent) city instead of showing error 500 page.

Fix code style

Conflicts:
	src/main/webapp/index.ftl
Merge pull request #5 from AlexWyrm/master

No error 500 for nonexistent cities
unit of measurement for temperature added
sample request: http://localhost:8080/moscow/ru/F