Honor nested .dockerignore exclusions in Docker build context (#1229)

Author: cristianrgreco

packages/testcontainers/fixtures/docker/docker-with-dockerignore-nested-exclusions/.dockerignore

@@ -0,0 +1,5 @@
+*
+!example2
+!example4/nested
+!example5/example5.txt
+!index.js

packages/testcontainers/fixtures/docker/docker-with-dockerignore-nested-exclusions/Dockerfile

@@ -0,0 +1,17 @@
+FROM node:10-alpine
+
+MAINTAINER Cristian Greco
+
+EXPOSE 8080
+
+RUN apk add --no-cache curl dumb-init
+
+RUN npm init -y \
+    && npm install express@4.16.4
+
+WORKDIR /opt/app
+
+COPY . .
+
+ENTRYPOINT ["/usr/bin/dumb-init", "--"]
+CMD ["node", "index.js"]

packages/testcontainers/fixtures/docker/docker-with-dockerignore-nested-exclusions/example1.txt

@@ -0,0 +1 @@
+hello world