Added pod spec file

Merge branch 'master' of https://github.com/nicklockwood/iRate

Updated to version 1.7.1

Fixed error in README file

Updated to version 1.6.2

Updated to version 1.6.1

Re-tagged 1.5.4/5 as 1.6 to better reflect significance of change

Conflicts:
	LICENCE.md
	RELEASE NOTES.md
	iRate/iRate.h
	iRate/iRate.m

Updated to version 1.5.3

Updated to version 1.5.2

Fixed example project scheme