Updated changelog

Backtrace agent support (#118)

* Backtrace agent support

* Do not read application version as 'backtrace.version'

Update Backtrace.podspec

Swift 5 support (#107)

* Swift 5 support

Migrate Backtrace-cocoa from swift 4.2 to swift 5
Update swift_version to ver 5.7
Update COCOAPODS to ver 1.12.0
Fix BacktraceLogger swift syntax

* Bump Backtrace SDK version

Bump Backtrace SDK version to 1.8.0-beta1
Bump Backtrace SDK MARKETING_VERSION to 1.8.0

* Prepare for 1.8.0-beta1 release

Update CHANGELOG.md
Resolve Podfile.lock

* Update project.pbxproj

Release 1.7.5 (#106)

* Mutable error message

* Attribute tests

* Version 1.7.5: version update and changelog update

* Changelog

prepare for release 1.7.4 (#98)