Add a gitignore

I noticed we don't have a git ignore. I think it is good practise to add one, it should help people using IDE's etc to see just things they have modified and not the whole build/eggs etc.

.gitignore

+.coverage
+build/
+dist/
+docs/_*
+tupak.egg-info/
+MANIFEST
+*.pyc
+*.png
+*.h5
+*.h5.old
+*.txt
+*.log
+*.dat
+*.version
+*.ipynb_checkpoints
+outdir/*
\ No newline at end of file