Adjust tests to check for case-insensitivity

Some file systems are case-insensitive, thus making differently cased
package names non-unique.

Also made me aware of the issue fixed in
fc6448ff.

Partly addresses https://github.com/wbond/package_control/issues/1028.

tests/test.py

@@ -125,6 +125,22 @@ def generate_test_methods(cls, stream):
     return cls
 
 
+# Very limited subclassing of dict class, which just suits our needs
+class CaseInsensitiveDict(dict):
+    @classmethod
+    def _k(cls, key):
+        return key.lower() if isinstance(key, str_cls) else key
+
+    def __getitem__(self, key):
+        return super(CaseInsensitiveDict, self).__getitem__(self._k(key))
+
+    def __setitem__(self, key, value):
+        super(CaseInsensitiveDict, self).__setitem__(self._k(key), value)
+
+    def __contains__(self, key):
+        return super(CaseInsensitiveDict, self).__contains__(self._k(key))
+
+
 def get_package_name(data):
     """Get "name" from a package with a workaround when it's not defined.
 
@@ -147,9 +163,10 @@ class TestContainer(object):
 
     @classmethod
     def setUpClass(cls):
-        cls.package_names = dict()
-        cls.previous_package_names = dict()
-        cls.dependency_names = dict()
+        cls.package_names = CaseInsensitiveDict()
+        cls.dependency_names = CaseInsensitiveDict()
+        # tuple of (prev_name, include, name); prev_name for case sensitivity
+        cls.previous_package_names = CaseInsensitiveDict()
 
     rel_b_reg = r'''^ (https:// github\.com/ [^/]+/ [^/]+
                       |https:// bitbucket\.org/ [^/]+/ [^/]+
@@ -216,11 +233,17 @@ class TestContainer(object):
                 self.fail("Package names must be unique: %s, previously "
                           "occured in %s"
                           % (pname, self.package_names[pname]))
-            elif pname in self.previous_package_names:
+            elif (
+                pname in self.previous_package_names
+                # check casing
+                and pname == self.previous_package_names[pname][0]
+            ):
+                print(pname, self.previous_package_names[pname][0])
                 self.fail("Package names can not occur as a name and as a "
                           "previous_name: %s, previously occured as "
-                          "previous_name in %s"
-                          % (pname, self.previous_package_names[pname]))
+                          "previous_name in %s: %s"
+                          % (pname, self.previous_package_names[pname][1],
+                             self.previous_package_names[pname][2]))
             else:
                 self.package_names[pname] = include
                 repo_package_names.append(pname)
@@ -291,7 +314,7 @@ class TestContainer(object):
                                   % (prev_name, self.package_names[prev_name]))
                     else:
                         self.previous_package_names[prev_name] = (
-                            "%s: %s" % (include, name)  # include package hint
+                            (prev_name, include, name)
                         )
 
         # Test for invalid characters (on file systems)