Add test with unified scheme.

Author: tapashmajumder

.travis.yml

@@ -5,13 +5,7 @@ before_install:
   - gem install xcpretty xcpretty-travis-formatter
 
 script:
-  - xcodebuild test -workspace swift-sdk.xcworkspace -scheme notification-extension-tests -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone X' -enableCodeCoverage YES CODE_SIGNING_REQUIRED=NO GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES GCC_GENERATE_TEST_COVERAGE_FILES=YES | xcpretty -f `xcpretty-travis-formatter`
-  - bash <(curl -s https://codecov.io/bash)
-  - xcodebuild test -workspace swift-sdk.xcworkspace -scheme iterable-sdk-tests -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone X' -enableCodeCoverage YES CODE_SIGNING_REQUIRED=NO GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES GCC_GENERATE_TEST_COVERAGE_FILES=YES | xcpretty -f `xcpretty-travis-formatter`
-  - bash <(curl -s https://codecov.io/bash)
-  - xcodebuild test -workspace swift-sdk.xcworkspace -scheme iterable-sdk-tests -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone 6s,OS=9.0' -enableCodeCoverage YES CODE_SIGNING_REQUIRED=NO GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES GCC_GENERATE_TEST_COVERAGE_FILES=YES | xcpretty -f `xcpretty-travis-formatter`
-  - bash <(curl -s https://codecov.io/bash)
-  - xcodebuild test -workspace swift-sdk.xcworkspace -scheme ui-tests -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone X' -enableCodeCoverage YES CODE_SIGNING_REQUIRED=NO GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES GCC_GENERATE_TEST_COVERAGE_FILES=YES | xcpretty -f `xcpretty-travis-formatter`
+  - xcodebuild test -workspace swift-sdk.xcworkspace -scheme swift-sdk -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone X' -enableCodeCoverage YES CODE_SIGNING_REQUIRED=NO GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES GCC_GENERATE_TEST_COVERAGE_FILES=YES | xcpretty -f `xcpretty-travis-formatter`
   - bash <(curl -s https://codecov.io/bash)
   - pod lib lint