Fix installation from git

If pystencils is installed from git and cython is not installed you get the error: gcc: error: pystencils/boundaries/createindexlistcython.c: No such file or directory. This is because the generated C file is not shipped and thus it is not available.

On pypi the C-file is shipped and thus it works.

Fixes #14 (closed)

doc/version_from_git.py

@@ -18,17 +18,20 @@ def version_number_from_git(tag_prefix='release/', sha_length=10, version_format
 
     version_strings = get_released_versions()
     version_strings.sort(key=StrictVersion)
-    latest_release = version_strings[-1]
-    commits_since_tag = subprocess.getoutput('git rev-list {}..HEAD --count'.format(tag_from_version(latest_release)))
-    sha = subprocess.getoutput('git rev-parse HEAD')[:sha_length]
-    is_dirty = len(subprocess.getoutput("git status --untracked-files=no -s")) > 0
+    if len(version_strings) > 0:
+        latest_release = version_strings[-1]
+        commits_since_tag = subprocess.getoutput('git rev-list {}..HEAD --count'.format(tag_from_version(latest_release)))
+        sha = subprocess.getoutput('git rev-parse HEAD')[:sha_length]
+        is_dirty = len(subprocess.getoutput("git status --untracked-files=no -s")) > 0
 
-    if int(commits_since_tag) == 0:
-        version_string = latest_release
-    else:
-        next_version = increment_version(latest_release)
-        version_string = version_format.format(version=next_version, commits=commits_since_tag, sha=sha)
+        if int(commits_since_tag) == 0:
+            version_string = latest_release
+        else:
+            next_version = increment_version(latest_release)
+            version_string = version_format.format(version=next_version, commits=commits_since_tag, sha=sha)
 
-    if is_dirty:
-        version_string += ".dirty"
-    return version_string
+        if is_dirty:
+            version_string += ".dirty"
+        return version_string
+    else:
+        return "development"