Ability to install modules using pip or conda (#380)

* Add support for pip and/or conda when installing modules
* Fix display versions for environments (fixes #378)
* Refactor installer to use the pip/conda module installer for installation of modules
* Performance improvement of detecting virtual env and setting it (fixes #372)
* Code refactor to ensure interpreter locators use the new DI framework
* Fixes #266

Author: DonJayamanne

.vscode/tasks.json

@@ -66,30 +66,6 @@
                     "fileLocation": "relative"
                 }
             ]
-        },
-        {
-            "label": "Hygiene (staged)",
-            "type": "gulp",
-            "task": "hygiene-staged",
-            "problemMatcher": [
-                "$tsc",
-                {
-                    "base": "$tslint5",
-                    "fileLocation": "relative"
-                }
-            ]
-        },
-        {
-            "label": "Hygiene (all)",
-            "type": "gulp",
-            "task": "hygiene",
-            "problemMatcher": [
-                "$tsc",
-                {
-                    "base": "$tslint5",
-                    "fileLocation": "relative"
-                }
-            ]
         }
     ]
 }