fix(reporter.junit): Add browser log output to JUnit.xml

Make the JUnit adapter inherit from base
Push all log message into system-out element of the junit xml file.

Closes #302
test: use reporter specified in config for e2e tests

E2E test framework was overriding the reporters on the commandline.
This meant that tests e2e tests for reporter were not even using the
reporters they were supposed testing.  The test now use the specified
reporters, even if they don't verify their outputs.