Release 1.5.3

# gpg: Signature made Thu May 24 22:49:47 2018 PDT
# gpg:                using RSA key 01195BB315DDA856
# gpg: Good signature from "Samuel Giddins <segiddins@segiddins.me>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 7B19 37A9 CF66 AEF6 52C9  4090 0119 5BB3 15DD A856

# Conflicts:
#	Gemfile.lock
#	lib/cocoapods/generator/xcconfig/aggregate_xcconfig.rb
#	spec/cocoapods-integration-specs
#	spec/unit/installer/xcode/pods_project_generator_spec.rb