THRIFT-4041: add ocaml and oasis to ubuntu and debian docker build images
Client: OCaml

This closes #1190
diff --git a/build/docker/debian/Dockerfile b/build/docker/debian/Dockerfile
index 7c15109..9a16951 100644
--- a/build/docker/debian/Dockerfile
+++ b/build/docker/debian/Dockerfile
@@ -183,6 +183,15 @@
 # Dart
 ENV PATH /usr/lib/dart/bin:$PATH
 
+# OCaml
+RUN echo 'deb http://ppa.launchpad.net/avsm/ppa/ubuntu trusty main' > /etc/apt/sources.list.d/avsm-official-ocaml.list && \
+    gpg --keyserver keyserver.ubuntu.com --recv 61707B09 && \
+    gpg --export --armor 61707B09 | apt-key add - && \
+    apt-get update && \
+    apt-get install -y ocaml opam && \
+    opam init && \
+    opam install oasis
+
 # Force utf8 locale to successfully build Haskell tf-random
 ENV LC_ALL C.UTF-8