error with debian build

I'm seeing an error whilst trying to build a .deb, please could you take a look, Thanks, Chris.

```
chris@venus:~/mapslicer/mapslicer-master$ ./deploy/linux/makedeb
Traceback (most recent call last):
File "", line 1, in
File "mapslicer/__init__.py", line 3, in
from main import MainFrame
File "mapslicer/main.py", line 11, in
import wizard
File "mapslicer/wizard.py", line 13, in
from wxgdal2tiles import wxGDAL2Tiles
File "mapslicer/wxgdal2tiles.py", line 8, in
from gdal2tiles import GDAL2Tiles
File "mapslicer/gdal2tiles.py", line 38, in
from osgeo import gdal
ImportError: No module named osgeo
mapslicer.py
mapslicer/
mapslicer/widgets.py
mapslicer/icons.py
mapslicer/preprocess.py
mapslicer/gdal2tiles.py
mapslicer/wizard.py
mapslicer/__init__.py
mapslicer/pp/
mapslicer/pp/pptransport.py
mapslicer/pp/__init__.py
mapslicer/pp/ppworker.py
mapslicer/pp/ppserver.py
mapslicer/pp/ppauto.py
mapslicer/gdalpreprocess.py
mapslicer/main.py
mapslicer/wxgdal2tiles.py
mapslicer/config.py
README.txt
deploy/linux/mapslicer.desktop
resources/icon.png
dpkg-buildpackage: warning: debian/changelog(l1): badly formatted heading line
LINE: mapslicer () unstable; urgency=low
dpkg-buildpackage: warning: debian/changelog(l2): found blank line where expected first heading
dpkg-buildpackage: warning: debian/changelog(l3): found change data where expected first heading
LINE: * Release.
Can't call method "as_string" on an undefined value at /usr/share/perl5/Dpkg/Changelog.pm line 249.
cp: cannot stat '/tmp/tmp.6N4xDoAez3/*.deb': No such file or directory
```