Various updates for 0.5.0 release

 - Update readme.

 - Add CHANGES.md.

 - Re-run notebooks and fix a bug in example notebook 1.

 - Bump version number in version.py to 0.5.0.

CHANGES.md

@@ -0,0 +1,3 @@
+## Changes in 0.5.0
+
+Initial released version.

README.md

@@ -10,39 +10,39 @@ Currently supported datasets:
 
 ## Setup
 
-xcube and cdsapi must be installed before the xcube_cds plugin.
+[xcube](https://github.com/dcs4cop/xcube) and cdsapi must be installed
+before the xcube_cds plugin.
 In order to use the xcube_cds plugin, you also need to obtain a CDS API key
 and write it to a configuration file. Additionally, you need to use the CDS
 website to agree to the terms of use for any datasets you acccess. These
 steps are described in more detail below.
 
 ### Install xcube
 
-[xcube](https://github.com/dcs4cop/xcube) can be installed from
-[conda-forge](https://conda-forge.org/) using the
-conda package manager, like this:
+xcube 0.5 can be built from source, like this:
 
 ```
-$ conda create --name xcube xcube>=0.4
+$ git clone https://github.com/dcs4cop/xcube.git
+$ cd xcube
+$ conda env create
 $ conda activate xcube
+$ python setup.py develop
 ```
 
-xcube can also be built from source, like this:
+Once xcube 0.5 becomes available on [conda-forge](https://conda-forge.org/),
+it can be installed using the conda package manager, like this:
 
 ```
-$ git clone https://github.com/dcs4cop/xcube.git
-$ cd xcube
-$ conda env create
+$ conda create --name xcube xcube>=0.5
 $ conda activate xcube
-$ python setup.py develop
 ```
 
 ### Install cdsapi
 
 xcube_cds makes use of the
-[cdsapi Python library](https://github.com/ecmwf/cdsapi) to connect to the CDS
-API, which is also available from conda-forge. You can install it into an
-xcube environment like this:
+[cdsapi Python library](https://github.com/ecmwf/cdsapi),
+which is available from conda-forge, to connect to the CDS API.
+You can install it into an xcube environment like this:
 
 ```
 $ conda activate xcube

examples/notebooks/Ex0-CDS-store-setup.ipynb

@@ -44,7 +44,7 @@
     {
      "data": {
       "text/plain": [
-       "'0.0.0.dev0'"
+       "'0.5.0'"
       ]
      },
      "execution_count": 1,
@@ -83,7 +83,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [
     {
@@ -92,7 +92,7 @@
        "('dataset',)"
       ]
      },
-     "execution_count": 5,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }