Docs: add a getting started for buildng and running on Mac

Author: jamesblackburn

docs/developing-conda-mac.md

@@ -0,0 +1,101 @@
+# Running on Mac OS X - tested on 10.13.4
+
+## Install XCode from the Mac App Store
+
+## Install the Mac OS X headers
+
+```
+xcode-select --install
+```
+
+## Install conda - create env - install anaconda
+
+https://conda.io/miniconda.html
+
+```
+~/Downloads/Miniconda3-latest-MacOSX-x86_64-2.sh
+```
+
+## Build and activate conda env
+
+```
+conda create -n 201804 python
+source activate 201804
+```
+
+## Install packages in the env
+
+```
+conda install anaconda
+conda install pymongo
+```
+
+## Build and install arctic
+
+```
+git clone [email protected]:manahl/arctic.git
+cd arctic
+python setup.py develop
+```
+
+## Run MongoD
+
+```
+mongod --dbpath mongo_tmp/
+```
+
+## Connect and test arctic
+
+```
+ipython
+from arctic import Arctic
+a = Arctic('localhost')
+a.initialize_library('test')
+l = a['test']
+l.write('thing', object())
+```
+
+## Issues
+
+### Not using the correct compiler on Mac OS X
+
+FIXME: setup.py needs patching to use anaconda cc / g++ directly
+
+
+### tzlocal issue with pytz == 1.5.1
+
+```
+  ```File "<frozen importlib._bootstrap>", line 441, in spec_from_loader
+  File "<frozen importlib._bootstrap_external>", line 544, in spec_from_file_location
+  File "/Users/james/miniconda3/envs/201804/lib/python3.6/site-packages/tzlocal-1.5.1-py3.6.egg/tzlocal/unix.py", line 77
+SyntaxError: invalid escape sequence \s
+```
+
+`pip install pytz==1.4`
+
+### Mongo not finding mongod
+
+```
+>               raise child_exception_type(errno_num, err_msg, err_filename)
+E               FileNotFoundError: [Errno 2] No such file or directory: '/usr/bin/mongod': '/usr/bin/mongod'
+```
+
+Point at the directory that contains the `mongod` command
+
+```
+export SERVER_FIXTURES_MONGO_BIN=/Users/james/bin/
+```
+
+### Tests hanging 
+
+This is a pytest-server-fixtures issue compatibility with MongoDB 3.6. 
+Use MongoDB 3.4...
+
+### lz4 compression issue
+
+```
+>   [lz4.decompress(y) for y in [lz4.compressHC(x) for x in _strarr]]
+E   AttributeError: module 'lz4' has no attribute 'compressHC'
+```
+
+Fix the integration test to be compatible with new lz4 `lz4.compress` /