Docker image for running ccminer with CPU

Start mining in 5 steps!

Build an image locally
```
make
```
Create a Makefile
```
cp Makefile.dist Makefile
```
Prepare the options you want to pass to ccminer. (For instance, generate the from zergpool.com)
Open Makefile in a text editor and in the last line replace --version with the options that you have prepared.
Start the docker container
```
make run
```