fix: better handling of case sensetivity

some packags like Django-Select2 install as lowercase, and the code
didn't expect that

plug/pip_resolve.py

@@ -28,8 +28,11 @@ def create_tree_of_packages_dependencies(dist_tree, packages_names, req_file_pat
     key_tree = dict((k.key, v) for k, v in tree.items())
 
     def get_children(n): return key_tree.get(n.key, [])
+    lowercase_pkgs_names = [p.lower() for p in packages_names]
     packages_as_dist_obj = [
-        p for p in nodes if p.key in packages_names or p.project_name in packages_names]
+        p for p in nodes if
+            p.key.lower() in lowercase_pkgs_names or
+            (p.project_name and p.project_name.lower()) in lowercase_pkgs_names]
 
     def create_children_recursive(root_package, key_tree):
         root_name = root_package[NAME].lower()

test/inspect.test.js

@@ -101,6 +101,20 @@ test('inspect', function (t) {
         },
       }, 'python-etcd is ok');
 
+      t.match(pkg.dependencies['django-select2'], {
+        name: 'django-select2',
+        version: '6.0.1',
+        from: [
+          'pip-app@0.0.0',
+          'django-select2@6.0.1',
+        ],
+        dependencies: {
+          'django-appconf': {
+            name: 'django-appconf',
+          },
+        },
+      }, 'django-select2 looks ok');
+
       t.end();
     });
 
@@ -199,6 +213,20 @@ test('transitive dep not installed, but with allowMissing option', function (t)
               },
             }, 'python-etcd is ok');
 
+            t.match(pkg.dependencies['django-select2'], {
+              name: 'django-select2',
+              version: '6.0.1',
+              from: [
+                'pip-app@0.0.0',
+                'django-select2@6.0.1',
+              ],
+              dependencies: {
+                'django-appconf': {
+                  name: 'django-appconf',
+                },
+              },
+            }, 'django-select2 looks ok');
+
             t.end();
           });
 

test/workspaces/pip-app/requirements.txt

@@ -1,4 +1,4 @@
 Jinja2==2.7.2
 Django==1.6.1
 python-etcd==0.4.5
-
+Django-Select2==6.0.1 # this version installs with lowercase so it catches a previous bug in pip_resolve.py