TYPO: section 02.06 do->to

Fix typo on 02.06-Boolean-Arrays-and-Masks

Author: jakevdp

notebooks/02.06-Boolean-Arrays-and-Masks.ipynb

@@ -890,7 +890,7 @@
  "source": [
  "What is returned is a one-dimensional array filled with all the values that meet this condition; in other words, all the values in positions at which the mask array is ``True``.\n",
  "\n",
- "We are then free do operate on these values as we wish.\n",
+ "We are then free to operate on these values as we wish.\n",
  "For example, we can compute some relevant statistics on our Seattle rain data:"
  ]
  },