Run P4C tests that require the behavioral model in Travis

Dockerfile

@@ -2,6 +2,7 @@ FROM ubuntu:14.04
 MAINTAINER Seth Fowler <seth.fowler@barefootnetworks.com>
 
 # Install dependencies.
+ENV DEBIAN_FRONTEND noninteractive
 RUN apt-get update && \
     apt-get install -y \
       automake \
@@ -19,6 +20,19 @@ RUN apt-get update && \
       python-scapy \
       tcpdump
 
+# Clone and build behavioral-model, which is needed by some tests.
+ENV BEHAVIORAL_MODEL_REPO https://github.com/sethfowler/behavioral-model.git
+ENV BEHAVIORAL_MODEL_TAG 4f85ec95da24
+RUN git clone --recursive $BEHAVIORAL_MODEL_REPO /behavioral-model && \
+    cd /behavioral-model && \
+    git reset --hard $BEHAVIORAL_MODEL_TAG && \
+    ./install_deps.sh && \
+    ./autogen.sh && \
+    ./configure && \
+    make -j8 && \
+    make install && \
+    ldconfig
+
 # Copy entire repository.
 COPY . /p4c/
 WORKDIR /p4c/