Added versioneer to better manage the versions

Author: hmaarrfk

.gitattributes

@@ -0,0 +1 @@
+picoscope/_version.py export-subst

.travis.yml

@@ -5,7 +5,7 @@ python:
   - "3.6"
   - "3.7-dev"
 
-install: pip install flake8
+install: pip install flake8 versioneer
 
 script: 
    - flake8 picoscope setup.py

MANIFEST.in

@@ -1,3 +1,5 @@
 include README.md
 include LICENSE.md
 include examples/*.py
+include versioneer.py
+include picoscope/_version.py

picoscope/__init__.py

@@ -1,6 +1,5 @@
 __author__ = "Colin O'Flynn, Mark Harfouche"
 __license__ = "FreeBSD"
-__version__ = "0.7.1"
 
 __all__ = ["ps2000",
            "ps2000a",
@@ -10,3 +9,8 @@
            "ps4000a",
            "ps5000a",
            "ps6000"]
+
+from ._version import get_versions
+__version__ = get_versions()['version']
+del get_versions
+