Add HDF5 support for Julia

* create `.juliarc.jl` start up script to point Julia to conda libraries, specifically the hdf5 libraries installed through the h5py package in the scipy stack
* add the HDF5 Julia package

Update README.md to document HDF5 addition

Add -F option to force config load

Add the -F flag to julia expression execution to load .juliarc.jl before execution.

all-spark-notebook/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/all-spark-notebook.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/all-spark-notebook.svg)
+
 # Jupyter Notebook Python, Scala, R, Spark, Mesos Stack
 
 ## What it Gives You

datascience-notebook/Dockerfile

@@ -52,4 +52,8 @@ RUN julia -e 'Pkg.add("IJulia")' && \
     mv /home/$NB_USER/.local/share/jupyter/kernels/* $CONDA_DIR/share/jupyter/kernels/ && \
     chmod -R go+rx $CONDA_DIR/share/jupyter && \
     rm -rf /home/$NB_USER/.local/share
-RUN julia -e 'Pkg.add("Gadfly")' && julia -e 'Pkg.add("RDatasets")'
+
+# Show Julia where conda libraries are
+# Add essential packages
+RUN echo 'push!(Sys.DL_LOAD_PATH, "/opt/conda/lib")' > /home/$NB_USER/.juliarc.jl && \
+    julia -e 'Pkg.add("Gadfly")' && julia -e 'Pkg.add("RDatasets")' && julia -F -e 'Pkg.add("HDF5")'

datascience-notebook/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/datascience-notebook.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/datascience-notebook.svg)
+
 # Jupyter Notebook Data Science Stack
 
 ## What it Gives You
@@ -7,7 +9,7 @@
 * pandas, matplotlib, scipy, seaborn, scikit-learn, scikit-image, sympy, cython, patsy, statsmodel, cloudpickle, dill, numba, bokeh pre-installed
 * Conda R v3.2.x and channel
 * plyr, devtools, dplyr, ggplot2, tidyr, shiny, rmarkdown, forecast, stringr, rsqlite, reshape2, nycflights13, caret, rcurl, and randomforest pre-installed
-* Julia v0.3.x with Gadfly and RDatasets pre-installed
+* Julia v0.3.x with Gadfly, RDatasets and HDF5 pre-installed
 * Unprivileged user `jovyan` (uid=1000, configurable, see options) in group `users` (gid=100) with ownership over `/home/jovyan` and `/opt/conda`
 * [tini](https://github.com/krallin/tini) as the container entrypoint and [start-notebook.sh](../minimal-notebook/start-notebook.sh) as the default command
 * Options for HTTPS, password auth, and passwordless `sudo`

minimal-kernel/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/minimal-kernel.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/minimal-kernel.svg)
+
 # Kernel Gateway Stack
 
 ## What it Gives You

minimal-notebook/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/minimal-notebook.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/minimal-notebook.svg)
+
 # Minimal Jupyter Notebook Stack
 
 ## What it Gives You

pyspark-notebook/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/pyspark-notebook.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/pyspark-notebook.svg)
+
 # Jupyter Notebook Python, Spark, Mesos Stack
 
 ## What it Gives You

r-notebook/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/r-notebook.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/r-notebook.svg)
+
 # Jupyter Notebook R Stack
 
 ## What it Gives You

scipy-notebook/README.md

+![docker pulls](https://img.shields.io/docker/pulls/jupyter/scipy-notebook.svg) ![docker stars](https://img.shields.io/docker/stars/jupyter/scipy-notebook.svg)
+
 # Jupyter Notebook Scientific Python Stack
 
 ## What it Gives You