warn when using an unstable version

setting the MONGOOSE_DISABLE_STABILITY_WARNING env variable
disables the warning
make; suppress warning msg in test
tests; fix a versioning test bug
Fixed versioning test

makes sure the expected order happens
updated; mocha to 1.12.0
script for continuously running tests
the push() tests for multidimensional arrays passing

These tests are now passing. This commit also contains a couple changes to existing tests to make them work with multidimensional arrays