Lamda query to requests and formatting edits

I've made formatting edits and changed the lamda sub-module to use requests per PR #97. Local tests still work. Also, I think that the sub-module will need refactoring to meet the API guidelines, I currently run it with:

    >>> from astroquery.lamda.core import LAMDAQuery
    >>> Q = LAMDAQuery()
    >>> t = Q.lamda_query(mol='co', query_type='erg_levels')