run pylint3 and fixed report

This commit adds a pylint configuration and fixed all found issues.

Signed-off-by: Claudius Heine <ch@denx.de>

kas/__main__.py

@@ -21,6 +21,9 @@
 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
+"""
+    The main entry point of kas, a setup tool for bitbake based projects
+"""
 
 from .kas import main