WIP breaking stuff: updating docker image build process for Python 3.6

This requires a new way to pass requirements.txt files to Docker (since
they now link to each other), as well as building Python ourselves (since
even Ubuntu 16.10 doesn't have a decent Python 3.6).

This is just a WIP commit, will be fixed soon(ish).

docker/2_build/build.sh

@@ -1,11 +1,33 @@
 #!/usr/bin/env bash
 
-mkdir -p ../3_run/wheelhouse;
-cp ../../requirements.txt .;
+# macOS does not support readlink -f, so we use greadlink instead
+if [ $(uname) == 'Darwin' ]; then
+    command -v greadlink 2>/dev/null 2>&1 || { echo >&2 "Install greadlink using brew."; exit 1; }
+    readlink='greadlink'
+else
+    readlink='readlink'
+fi
 
-docker build -t pillar_build -f build.docker .;
-docker run --rm \
-       -v "$(pwd)"/../3_run/wheelhouse:/data/wheelhouse \
-       pillar_build;
+TOPDEVDIR="$($readlink -f ../../..)"
+echo "Top-level development dir is $TOPDEVDIR"
 
-rm requirements.txt;
+PYTHON=$($readlink -f ../3_run/python)
+WHEELHOUSE="$($readlink -f ../3_run/wheelhouse)"
+if [ -z "$WHEELHOUSE" -o -z "$PYTHON" ]; then
+    echo "Error, ../3_run might not exist." >&2
+    exit 2
+fi
+
+mkdir -p "$WHEELHOUSE" "$PYTHON"
+echo "Wheelhouse is $WHEELHOUSE"
+echo "Python will be built to $PYTHON"
+
+docker build -t pillar_build -f build.docker .
+#docker run --rm \
+#    -v "$WHEELHOUSE:/data/wheelhouse" \
+#    -v "$TOPDEVDIR:/data/topdev" \
+#    -v "$PYTHON:/data/python" \
+#    pillar_build
+
+# RUN cd Python-3.6.0/ && ./myconfigure
+# RUN cd Python-3.6.0/ && make -j8 install