Remove Gemfile.lock; add to .gitignore

Add development dependency for `jasmine-core` gem and `rspec` to limit
them to 1.3.x and 2.14.x respectively. The `jasmine` wrapper gem allows
for any version of `jasmine-core` >= 1.3.0 and `rspec` >= 2.5.0, causing
versions 2.x and 3.1 to be installed and the tests to fail.

I can submit a subsequent pull request to update dependencies.