Ubuntu install - fixes 86

Fixes #86.

You can actually test the shell script by switching `0.1.0` to `0.0.1`.
The correct way to append to a delimited list in shell is like this:

```
FOO=${FOO:+${FOO}:}newvalue
```

So, for example

```
export PATH=${PATH:+${PATH}:}newvalue
```

Also you should avoid backtick style substitution for portability.  So

```
export PATH=${PATH:+${PATH}:}${PWD}/bin
```

And you should quote variables to avoid having problems with spaces.  So:

```
export PATH="${PATH:+${PATH}:}${PWD}/bin"
```