Fix command line compilation error, due to generics craziness.
When compiling at the command line, via mvn compile, compilation fails with the following error:
[ERROR] /Users/tobli/Development/jdbcmetrics/src/test/java/com/soulgalore/jdbcmetrics/driver/WhenDriverIsRegistered.java:[19,2] cannot find symbol
symbol  : method assertThat(java.util.List<java.sql.Driver>,org.hamcrest.Matcher<java.lang.Iterable<? super java.lang.Object>>)
location: class com.soulgalore.jdbcmetrics.driver.WhenDriverIsRegistered
This issue is noted in http://code.google.com/p/hamcrest/issues/detail?id=167
Work around by replacing Hamcrest matchers with for-loop.
Fix order dependency in tests by resetting static variable before every test.
Sometimes when running tests (always from within IntelliJ IDEA) the headersShouldBeSetWhenRightHeaderIsSupplied test will fail. This is because the QueryThreadLocal state was not cleared between tests. Fix by clearing thread local in setUp.
Silence sl4j warnings when running tests.
When running tests sl4j would print warnings in the logs.
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Prevent this by adding slf4j-simple.jar in the test scope, to enable a proper logger for the tests.