Convert entire OpenRAM to use python3. Works with Python 3.6.

Major changes:
Remove mpmath library and use numpy instead.
Convert bytes to new bytearrays.
Fix class name check for duplicate gds instances.
Add explicit integer conversion from floats.
Fix importlib reload from importlib library
Fix new key/index syntax issues.
Fix filter and map conversion to lists.
Fix deprecation warnings.
Fix Circuits vs Netlist in Magic LVS results.
Fix file closing warnings.

compiler/sram.py

@@ -20,6 +20,7 @@ class sram(design.design):
     """
     def __init__(self, word_size, num_words, num_banks, name):
 
+        from importlib import reload
         c = reload(__import__(OPTS.control_logic))
         self.mod_control_logic = getattr(c, OPTS.control_logic)
 
@@ -96,8 +97,8 @@ class sram(design.design):
         self.words_per_row = self.amend_words_per_row(self.tentative_num_rows, self.words_per_row)
         
         # Fix the number of columns and rows
-        self.num_cols = self.words_per_row*self.word_size
-        self.num_rows = self.num_words_per_bank/self.words_per_row
+        self.num_cols = int(self.words_per_row*self.word_size)
+        self.num_rows = int(self.num_words_per_bank/self.words_per_row)
 
         # Compute the address and bank sizes
         self.row_addr_size = int(log(self.num_rows, 2))
@@ -125,11 +126,11 @@ class sram(design.design):
         # Recompute the words per row given a hard max
         if(tentative_num_rows > 512):
             debug.check(tentative_num_rows*words_per_row <= 2048, "Number of words exceeds 2048")
-            return words_per_row*tentative_num_rows/512
+            return int(words_per_row*tentative_num_rows/512)
         # Recompute the words per row given a hard min
         if(tentative_num_rows < 16):
             debug.check(tentative_num_rows*words_per_row >= 16, "Minimum number of rows is 16, but given {0}".format(tentative_num_rows))
-            return words_per_row*tentative_num_rows/16
+            return int(words_per_row*tentative_num_rows/16)
             
         return words_per_row
 
@@ -1092,9 +1093,9 @@ class sram(design.design):
         else:
             # Use generated spice file for characterization
             sp_file = spname
-        
+        print(sys.path)
         # Characterize the design
-        start_time = datetime.datetime.now()        
+        start_time = datetime.datetime.now()
         from characterizer import lib
         print("LIB: Characterizing... ")
         if OPTS.analytical_delay:
@@ -1104,7 +1105,7 @@ class sram(design.design):
                 print("Performing simulation-based characterization with {}".format(OPTS.spice_name))
             if OPTS.trim_netlist:
                 print("Trimming netlist to speed up characterization.")
-        lib.lib(out_dir=OPTS.output_path, sram=self, sp_file=sp_file)
+        lib(out_dir=OPTS.output_path, sram=self, sp_file=sp_file)
         print_time("Characterization", datetime.datetime.now(), start_time)
 
         # Write the layout