Update pip unsupported error message (#2852)

src/unsupported_python/setup.py

@@ -17,23 +17,30 @@ class InstallEngine(install):
     def run(self):
         msg = ("""
 
+
         ==================================================================================
-        ERROR
+        TURICREATE ERROR
 
         If you see this message, pip install did not find an available binary package
-        for your system. Supported platforms are:
+        for your system.
+
+        Supported Platforms:
+            * macOS 10.12+ x86_64.
+            * Linux x86_64 (including WSL on Windows 10).
 
-        * Linux x86_64 (including WSL on Windows 10).
-        * macOS 10.12+ x86_64.
-        * Python 2.7, 3.5, or 3.6.
-        * Python 3.7 macOS only.
+        Support Python Versions:
+            * 2.7
+            * 3.5
+            * 3.6
+            * 3.7
 
-        Other possible causes of this error are:
 
-        * Outdated pip version (try `pip install -U pip`).
+        Another possible cause of this error is an outdated pip version. Try:
+            `pip install -U pip`
 
         ==================================================================================
 
+
         """)
         sys.stderr.write(msg)
         sys.exit(1)