RUMM-369 Fix Carthage for Xcode 11.3

[ncreated]

What and why?

🐞 Fixing #71, where it was reported that carthage update doesn't work for Xcode 11.3.

How?

Xcode 11.3 expects *.modulemap to be put inside include/ directory for DatadogPrivate.
This is different in Xcode 11.4 where *.modulemap can be put anywhere.

In result carthage update was failing with:

/usr/bin/xcrun xcodebuild -workspace /Carthage/Checkouts/dd-sdk-ios/instrumented-tests/Integration/Integration.xcworkspace CODE_SIGNING_REQUIRED=NO 

...

xcodebuild: error: Could not resolve package dependencies:
  package has unsupported layout; modulemap '/Carthage/Checkouts/dd-sdk-ios/Datadog/DatadogPrivate/module.modulemap' should be inside the 'include' directory

💡 Why carthage update builds Integration.xcworkspace? Well, Carthage scans recursively its Checkouts/ directory and builds every .xcodeproj and .xcworkspace it finds and there is no option to make it ignore particular schemes.

🎁 I also updated spm-example project to use 1.0.2 pre-release tag, so the same problem doesn't happen there when building Datadog dependency.

🧪 I validated all dependency managers by running unit + UI tests:

• Xcode 11.3.1 (11C505) - OK for Carthage, Cocoapods and SPM both on 📱 and Simulator;
• Xcode 11.4 (11E146) - OK for Carthage, Cocoapods and SPM both on 📱 and Simulator.

💡 This PR also sets the exactVersion of Datadog SPM package used by spm-example project to a tag on this branch. This is to make this PR correct for Xcode 11.3. We're OK with merging this to master as spm-example will be re-done soon.

Review checklist

• Feature or bugfix MUST have appropriate tests (unit, integration)
• Make sure each commit and the PR mention the Issue number or JIRA reference

[ncreated]

• I forgot to bump the sdkVersion, doing it right now.

[buranmert]

We should leave a note in this PR on the change in spm-example project.
It requires some context to understand the change.