Removed self in super call that causes "got multiple values for keyword argument" error.

This bug fix is required for pull request #19
Merge pull request #20 from asreimer/patch-6

Removed self in super call that causes "got multiple values for keyword argument" error.
Merge branch 'patch-4' of https://github.com/asreimer/davitpy-usask into development

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corrected some minor errors
Merge branch 'master' of https://github.com/vtsuperdarn/davitpy
fixed some syntax warnings, typo in documentation
Merge branch 'patch-5' of https://github.com/asreimer/davitpy-usask into development

# Please enter a commit message to explain why this merge is necessary,
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Merge branch 'master' into development
fixed conflicts from merge from upstream