diff --git a/.appveyor.yml b/.appveyor.yml
index bf7b6366..62de9157 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -14,5 +14,4 @@ build: off
 
 test_script:
   - cd ..
-  #- "if %PYTHON%==C:\\Python36-x64 (%PYTHON%\\python -m pytest pymarketcap/tests -vs --end2end) else (%PYTHON%\\python -m pytest pymarketcap/tests -vs)"
-  - tox
\ No newline at end of file
+  - "if %PYTHON%==C:\\Python36-x64 (%PYTHON%\\python -m pytest pymarketcap/tests -vs --end2end) else (%PYTHON%\\python -m pytest pymarketcap/tests -vs)"
diff --git a/.travis.yml b/.travis.yml
index 68b9d6c6..50e27763 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,20 +4,23 @@ os:
   - linux
 
 python:
+  - "3.6"
   - "3.6.3"
+  - "3.6.4"
+  - "nightly"
   - "3.7-dev"
 
 install:
   # urllib version in Python3.6
   - pip install -r dev-requirements.txt
-  - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then make install-light; else make install; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == "3.6" ]]; then make install-light; else make install; fi
 before_script:
   - python -m pip install --upgrade pip
   - echo $TRAVIS_PYTHON_VERSION
 script:
-  - tox
+  - if [[ $TRAVIS_PYTHON_VERSION == "3.6" ]]; then make test-end2end; else make test; fi
 branches:
   only:
     - master
 after_success:
-  - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then coveralls; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == "3.6" ]]; then coveralls; fi
diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index b16dc9e4..4de39df6 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -45,7 +45,7 @@ TODO
 - Add posibility of return asynchronous responses in ``pandas.DataFrames`` objects or download it in ``.csv`` format.
 - Include links to source code in documentation reference.
 - Assert names consistence in responses fields between methods.
-
+- Reintegrate support for Python3.6.4
 --------------
 
 How does pymarketcap works in depth?
diff --git a/Makefile b/Makefile
index 199d6cff..7d65b5cf 100644
--- a/Makefile
+++ b/Makefile
@@ -33,8 +33,8 @@ reinstall:
 clean:
 	sudo rm -Rf .pytest_cache/ .tox/ build/ dist/ pymarketcap.egg-info/
 	sudo find . -type d -name "__pycache__" -exec rm -r {} +
-	sudo rm pymarketcap/*.c pymarketcap/*.so
 	sudo find . -type d -name "_build" -exec rm -r {} +
+	sudo rm pymarketcap/*.c pymarketcap/*.so
 
 test:
 	pytest tests -vs
diff --git a/README.rst b/README.rst
index b2b10112..2c0256ec 100644
--- a/README.rst
+++ b/README.rst
@@ -16,7 +16,7 @@ pymarketcap
 `coinmarketcap <http://coinmarketcap.com/>`__ API and website. Consist
 of a cythonized scraper and and API wrapper built with libcurl, but is
 posible to compile a lightweight version with standard ``urllib``
-library instead. Only works in Python3.6+
+library instead. Only works in Python3.7+
 
 Install
 -------
diff --git a/dev-requirements.txt b/dev-requirements.txt
index dbaab24d..47678005 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,5 +1,4 @@
 pytest>=3.4.0
-tox>=3.0.0rc1
 tqdm>=4.19.5
 tabulate>=0.8.2
 sphinx>=1.7.0
diff --git a/pymarketcap/__init__.py b/pymarketcap/__init__.py
index 662292ee..4b4d01d3 100644
--- a/pymarketcap/__init__.py
+++ b/pymarketcap/__init__.py
@@ -5,7 +5,7 @@
 import sys
 
 __title__ = "pymarketcap"
-__version__ = "3.9.142"
+__version__ = "3.9.144"
 __version_info__ = (int(num) for num in __version__.split("."))
 __author__ = "Alvaro Mondejar Rubio <mondejar1994@gmail.com>"
 __repo__ = "https://github.com/mondeja/pymarketcap"
diff --git a/pymarketcap/core.pyx b/pymarketcap/core.pyx
index 30bf99a0..83ce3ef3 100644
--- a/pymarketcap/core.pyx
+++ b/pymarketcap/core.pyx
@@ -323,7 +323,10 @@ cdef class Pymarketcap:
     @property
     def ticker_badges(self):
         """Badges in wich you can convert prices in ``ticker()`` method."""
-        return
+        return ["AUD", "BRL", "CAD", "CHF", "CLP", "CNY", "CZK", "DKK",
+                "EUR", "GBP", "HKD", "HUF", "IDR", "ILS", "INR", "JPY",
+                "KRW", "MXN", "MYR", "NOK", "NZD", "PHP", "PKR", "PLN",
+                "RUB", "SEK", "SGD", "THB", "TRY", "TWD", "USD", "ZAR"]
 
     cpdef ticker(self, currency=None, limit=0, start=0, convert="USD"):
         """Get currencies with other aditional data.
@@ -347,13 +350,12 @@ cdef class Pymarketcap:
         Returns (dict/list):
             The type depends if currency param is provided or not.
         """
-        cdef bytes url
         cdef short i, len_i
         if not currency:
-            url = b"https://api.coinmarketcap.com/v1/ticker/?%s" % b"limit=%d" % limit
-            url += b"&start=%d" % start
-            url += b"&convert=%s" % convert.encode()
-            res = self._get(url)
+            url =  "https://api.coinmarketcap.com/v1/ticker/?limit=%d" % limit
+            url += "&start=%d" % start
+            url += "&convert=%s" % convert
+            res = self._get(url.encode())
             response = loads(re_sub(r'"(-*\d+(?:\.\d+)?)"', r"\1", res))
             len_i = len(response)
             for i in range(len_i):
@@ -361,9 +363,9 @@ cdef class Pymarketcap:
         else:
             if self._is_symbol(currency):
                 currency = self.correspondences[currency]
-            url = b"https://api.coinmarketcap.com/v1/ticker/%s" % currency.encode()
-            url += b"?convert=%s" % convert.encode()
-            res = self._get(url)
+            url = "https://api.coinmarketcap.com/v1/ticker/%s" % currency
+            url += "?convert=%s" % convert
+            res = self._get(url.encode())
             response = loads(re_sub(r'"(-*\d+(?:\.\d+)?)"', r"\1", res))[0]
             response["symbol"] = str(response["symbol"])
         return response
@@ -533,7 +535,6 @@ cdef class Pymarketcap:
         Returns (list):
             Historical dayly OHLC for a currency.
         """
-        cdef bytes url, _start, _end
         response = {}
 
         if self._is_symbol(name):
@@ -547,13 +548,13 @@ cdef class Pymarketcap:
                     response["symbol"] = symbol
                     break
 
-        url = b"https://coinmarketcap.com/currencies/%s/historical-data/" % name.encode()
-        _start = b"%d" % start.year + b"%02d" % start.month + b"%02d" % start.day
-        _end = b"%d" % end.year + b"%02d" % end.month + b"%02d" % end.day
-        url += b"?start=%s" % _start + b"&" + b"end=%s" % _end
+        url = "https://coinmarketcap.com/currencies/%s/historical-data/" % name
+        _start = "%d" % start.year + "%02d" % start.month + "%02d" % start.day
+        _end = "%d" % end.year + "%02d" % end.month + "%02d" % end.day
+        url += "?start=%s" % _start + "&" + "end=%s" % _end
 
         try:
-            res = self._get(url)[50000:]
+            res = self._get(url.encode())[50000:]
         except CoinmarketcapHTTPError404:
             if name not in self.coins:
                 raise ValueError("%s is not a valid currrency name. See 'symbols'" % name \
@@ -596,10 +597,9 @@ cdef class Pymarketcap:
             Data from a exchange. Keys: ``"name"``, ``"website"``,
             ``"volume"`` (total), ``"social"`` and ``"markets"``.
         """
-        cdef bytes url
-        url = b"https://coinmarketcap.com/exchanges/%s/" % name.encode()
+        url = "https://coinmarketcap.com/exchanges/%s/" % name
         try:
-            res = self._get(url)[20000:]
+            res = self._get(url.encode())[20000:]
         except CoinmarketcapHTTPError404:
             if name not in self.exchange_slugs:
                 raise ValueError("%s is not a valid exchange name. See exchange_slugs" % name \
diff --git a/pymarketcap/curl.pyx b/pymarketcap/curl.pyx
index 999fcbee..88428046 100644
--- a/pymarketcap/curl.pyx
+++ b/pymarketcap/curl.pyx
@@ -39,7 +39,7 @@ cpdef Response get_to_memory(const char *url, long timeout, bint debug):
     cdef long true = 1L
     version = curl_version()
     cdef CURL *curl = curl_easy_init()
-    cdef const char *user_agent = "pymarketcap 3.9.142"
+    cdef const char *user_agent = "pymarketcap 3.9.144"
     cdef const char *accept_encoding = "gzip, deflate"
     cdef char *raw_body
 
diff --git a/setup.py b/setup.py
index 432237a4..53a5a058 100644
--- a/setup.py
+++ b/setup.py
@@ -156,8 +156,7 @@ def declare_cython_extension(ext_name, libraries=None):
     with open(core_path, "w") as f:
         f.writelines(content)
 
-ext_modules = cythonize(ext_modules,
-                       compiler_directives={'linetrace': True})
+ext_modules = cythonize(ext_modules)
 
 
 # ===========  Package metadata  ===========
@@ -173,7 +172,7 @@ def declare_cython_extension(ext_name, libraries=None):
 
 install = setup(
     name = "pymarketcap",
-    version = "3.9.142",
+    version = "3.9.144",
     url = "https://github.com/mondeja/pymarketcap",
     download_url = "https://github.com/mondeja/pymarketcap/archive/master.zip",
     author = author,
diff --git a/tests/conftest.py b/tests/conftest.py
index 1eb989fc..af57d39c 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,9 +1,13 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+import os
+import sys
 import asyncio
 import pytest
 
+sys.path.append(os.path.join(os.getcwd(), "pymarketcap"))
+
 def pytest_addoption(parser):
     parser.addoption("--end2end", action="store_true",
                      default=False, help="Run slower tests.")
@@ -24,3 +28,4 @@ def event_loop():
     #loop.close()
     pass
 
+
diff --git a/tests/test_sync_core/test_public_api/test_ticker.py b/tests/test_sync_core/test_public_api/test_ticker.py
index 0d515787..65290310 100644
--- a/tests/test_sync_core/test_public_api/test_ticker.py
+++ b/tests/test_sync_core/test_public_api/test_ticker.py
@@ -37,7 +37,7 @@ def assert_types(res):
         if key in map_types:
             type_test(map_types, key, value)
         else:
-            assert isinstance(value, (float, type(None)))
+            assert isinstance(value, (float, int, type(None)))
 
 
 def test_consistence():