Do not look for version number on editable pip packages (#39)

If the user has a local python site and installed editable packages,
they will appear in the output of `pip freeze` in a different format
than other installed packages.

colcon_bundle/installer/base_pip_installer.py

@@ -111,4 +111,12 @@ def _generate_metadata(self, python_pip_args):
     def split_package_version(package_version):
         """Split package==3.2.3 pip freeze output."""
         split_string = package_version.split('==')
+        # TODO: This shouldn't be necessary if we fix #40 since we
+        # should never install packages as editable
+        if len(split_string) < 2 and '-e' in package_version:
+            # Package is installed with --editable flag, and formatted
+            # differently. Does not have a version number.
+            # format: -e git+https://<repo>@<commit_hash>#egg=<package_name>.
+            split_string = package_version.split('=')
+            return {'name': split_string[1]}
         return {'name': split_string[0], 'version': split_string[1]}