Remove tester class

[SaganBolliger]

• Deleted Tester class and TesterTest unit tests.
• Modified CMakeLists to remove the old Tester build instructions.
• Commented out dependencies on Tester in already commented out math tests (see Unittests missing for critical code in math/*Matrix*  #376)
• Moved initialization previously done in Tester::init into PathTest::PathTest for unit test that depends on that initialization (it was the only unit test that depended on that initialization).
• Removed references to Tester from UnitTestMain.cpp test runner script

This PR concludes the porting off all nupic.core tests to gtest, and so it fixes #208.

@scottpurdy

[numenta-ci]

By analyzing the blame information on this pull request, we identified @scottpurdy, @utensil and @david-ragazzi to be potential reviewers

[scottpurdy]

I think you can remove src/test/unit/UnitTestMain.cpp and simply link against the gtest_main library that comes with googletest.

[SaganBolliger]

@scottpurdy Do you have a reference for not including a main() function and therefore being able to delete UnitTestMain.cpp?

[scottpurdy]

@SaganBolliger - Does this help? http://stackoverflow.com/a/21479008

[SaganBolliger]

@scottpurdy As we discussed, the current installation of gtest does not include gtest_main. I've opened #815, which describes this.

[scottpurdy]

I'd say delete the test headers rather than leaving them commented out. The source files are fine to leave commented though.

[scottpurdy]

Done reviewing.