Correct the spelling of CocoaPods in README

[ReadmeCritic]

This pull requests corrects the spelling of CocoaPods 🤓
https://github.com/CocoaPods/shared_resources/tree/master/media

One day I’ll make a bot that looks through the READMEs of all Pods, looks to see if it uses “Cocoapods” and PRs “CocoaPods” :D

— Ørta (@orta) February 10, 2016

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[codecov-io]

Current coverage is 100.00%

Merging #2 into development will not affect coverage as of 53c2e1c

@@            development      #2   diff @@
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  Files                 4       4       
  Stmts               176     176       
  Branches              0       0       
  Methods               0               
===========================================
  Hit                 176     176       
  Partial               0       0       
  Missed                0       0       

Review entire Coverage Diff as of 53c2e1c

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