Add post jdk8 solution for first test of exercise 2.
Add a second example for the filtering & collecting test.
Add a second example for the filtering & collecting test.
Reinstate accidentally removed jdk8 solution for exercise 1.
Add a jdk 8 solution for the second test.
Add another filter example.
Add another filter example.

Conflicts:

	src/main/java/org/adoptopenjdk/lambda/tutorial/exercise2/ElectoralDistrict.java
clarify what I'm talking about when I say inference 'is no there yet'
clarify what I'm talking about when I say inference 'is no there yet'
Add lambda solutions for exercise 2.
Remove unused imports in uncompleted branch.
Add javadoc for the final unit test for filtering.
Add javadoc for the final unit test for filtering.
Update README.md
Replace all anonymous implementations of FeatureMatcher with call to factory method given an extractor function.
Replace all anonymous implementations of FeatureMatcher with call to factory method given an extractor function.
Add a third exercise: mapping.
Add a third exercise: mapping.
Add three tests for mapping behaviour.
Add three tests for mapping behaviour.