Use dotnet:2.0-sdk and add env vars to dotnetcore2.0 Dockerfile

dotnetcore2.0/run/Dockerfile

@@ -1,17 +1,21 @@
-FROM microsoft/aspnetcore-build AS builder
+FROM microsoft/dotnet:2.0-sdk
 WORKDIR /source
 
-# caches restore result by copying csproj file separately
+# cache restore result
 COPY MockBootstraps/*.csproj .
 RUN dotnet restore
 
-# copies the rest of your code
+# copy the rest of the code
 COPY MockBootstraps/ .
 RUN dotnet publish --output /app/ --configuration Release
 
 
 FROM lambci/lambda-base
 
+ENV PATH=/var/lang/bin:/usr/local/bin:/usr/bin/:/bin \
+    LD_LIBRARY_PATH=/var/lang/lib:/lib64:/usr/lib64:/var/runtime:/var/runtime/lib:/var/task:/var/task/lib \
+    AWS_EXECUTION_ENV=AWS_Lambda_dotnetcore2.0
+
 RUN rm -rf /var/runtime /var/lang && \
   curl https://lambci.s3.amazonaws.com/fs/dotnetcore2.0.tgz | tar -zx -C /