Fix sed command to resolve app version

Author: andreyleskov

appveyor.yml

@@ -45,7 +45,7 @@ build_script:
     echo changing API yaml definition version to $APP_VERSION
     #MacOS version:
     #sed -i '' -e 's/\(.*version:.*\)/version: $APP_VERSION/g' MightyCalcAPI.yaml
-    sed -i 's/\(.*version:.*\)/  version: $APP_VERSION/g' MightyCalcAPI.yaml
+    sed -i "s/\(.*version:.*\)/  version: $APP_VERSION/g" MightyCalcAPI.yaml
 
     docker build . --target=build-env -t mightycalc-test:local
     docker build . -t aleskov/mightycalc:latest -t aleskov/mightycalc:$APP_VERSION