openalpr 1.2 (new formula)

Hopefully this formula will get a little simpler once/if my upstream pull
request is accepted:

https://github.com/openalpr/openalpr/pull/55

A notable one-off in this formula is that I couldn't include a "depend_on" for tesseract, as the formula depends on the "--devel" version of tesseract.  See the "caveats" method for more info.
Can this test be modified to do something more substantial than e.g. `--version` or `--help`? See `cmake.rb` for an example of an application formula with a good test and `tinyxml2.rb` for an example of a library formula with a good test. Thanks!