ci(security): Enable SourceClear (#135)

* ci(security): Enable SourceClear

Author: nchilada

.travis.yml

@@ -47,6 +47,8 @@ jobs:
       dotnet: 2.1.502
       install:
         - dotnet restore OptimizelySDK.NetStandard16/OptimizelySDK.NetStandard16.csproj
+      addons:
+        srcclr: true
       script:
         # strongname signing is taken care of in build step
         - dotnet build OptimizelySDK.NetStandard16/OptimizelySDK.NetStandard16.csproj /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=$TRAVIS_BUILD_DIR/keypair.snk