+ add HEAD request

Merge branch 'master' of https://github.com/silver-lu/empty-webserver

Conflicts:
	src/main/java/com/undecided/handlers/HttpMethodHandlerFactory.java
	src/main/java/com/undecided/handlers/requestmethod/HttpPutMethodHandler.java
	src/test/java/com/undecided/responses/responsecode/ServerRedirectResponseTest.java
	src/test/java/com/undecided/responses/responsetype/ServerGetFileResponseTest.java
Merge branch 'master' of https://github.com/silver-lu/empty-webserver