v0.3.0

• Use Python requests instead of the native HTTPConnection object

• Optimized row_values and col_values

• Optimized row_values and col_values
  Removed the _fetch_cells call for each method. This eliminates the
  adverse effect on runtime for large worksheets.

  Fixes #285, #190, #179, and #113

• Optimized row_values and col_values
  Removed the _fetch_cells call for each method. This eliminates the
  adverse effect on runtime for large worksheets.

  Fixes #285, #190, #179, and #113

• Altered insert_row semantics to utilize range
  This avoids issuing one API request per cell to retrieve the Cell
  objects after the insertion row. This provides a significant speed-up
  for insertions at the beginning of large sheets.

• Added mock tests for Travis (MockSpreadsheetTest)

• Fixed XML header issue with Python 3

• Fixed Worksheet.export function and associated test

• Added spreadsheet feed helper

• Add CellNotFound to module exports
  Fixes #88

• Fixed utf8 encoding error caused by duplicate XML declarations

• Fixed AttributeError when URLError caught by HTTPError catch block
  Fixes #257

• Added __iter__ method to Spreadsheet class

• Fixed export test

• Switched tests to oauth