Use latest java-parent

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Update license header

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added null-analysis

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added missing JavaDocs

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added default nonnull-behavior

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added missing JavaDocs

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added missing JavaDocs

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added default nonnull-analysis 

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added missing JavaDocs

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added JavaDocs

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added default module for IMessageConveyor for English error messages

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Fixed constructor construction.

'needsStringConstructor' was missing a complement operator, which leads
the following code to pick the wrong constructor, without the provided
error message.

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Fixed test for illegal input.

An illegal input should throw an IllegalStateException as defined by the
InsuranceCompany::calculateCover method.

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Removed illegal tests.

Since we are using nonnull-analysis, we no longer need implementation +
test cases which check null-contracts.

Signed-off-by: Sebastian Hoß <mail@shoss.de>
Added @Nullable annotation for injected field.

Without the annotation FindBugs will complain that the field is not
initialized, since FindBugs doesn't know about dependency injection.

Signed-off-by: Sebastian Hoß <mail@shoss.de>