Bump version to 0.5.0-alpha
Bump version to 0.5.0-alpha

bagelbits/pep257,GreenSteam/pep257,tescalada/pydocstyle,jmullan/pep257,PyCQA/pydocstyle,Nurdok/pydocstyle,glennmatthews/pep257,jbeezley/pep257,jayvdb/pep257,codehs/pep257,13steinj/pep257,pombredanne/pep257,Nurdok/pep257,farmersez/pydocstyle