Bump jasmine-node

to fix failing Travis build
Classic Test Runner: use `runIsolated` by default

The link "Debug this campaign" on attester status page
now leads to the page which runs each test in isolation,
which helps avoiding certain errors if the test modifies
global execution environment.
fix #90 Classic Test Runner: unable to reload test suite

When using AT <1.6.1, timestamped requests for `MainTestSuite` were sent
but the server ignored them. This commit allows timestamped requests
which fixes the issue with reloading test suites.

Close #98
fix #16 task restart mechanism when a browser is disconnected

Before this commit, when a browser was disconnected while executing a
task, the task was considered as failed.
This commit automatically queues again those interrupted tasks so that
they are executed again (with a maximum number of restarts, so that
tasks which make a browser crash do not lead to a never ending campaign).

Close #100
Integrating selenium-java-robot.

Close #102
Custom test types

Change the way test types are loaded in order to allow creating custom plugins.
The logic now is the following

- try to resolve the test type inside the repository
- if missing require `attester-type`