add gmusicapi python package

as well as several dependencies. Tested with a personal project that
relies on gmusicapi

pkgs/top-level/python-packages.nix

@@ -416,6 +416,20 @@ let
     };
   };
 
+  appdirs = buildPythonPackage rec {
+    name = "appdirs-1.4.0";
+
+    src = pkgs.fetchurl {
+      url = "https://pypi.python.org/packages/source/a/appdirs/appdirs-1.4.0.tar.gz";
+      md5 = "1d17b4c9694ab84794e228f28dc3275b";
+    };
+
+    meta = with stdenv.lib; {
+      description = "A python module for determining appropriate platform-specific dirs";
+      homepage = http://github.com/ActiveState/appdirs;
+      license = licenses.mit;
+    };
+  };
 
   application = buildPythonPackage rec {
     name = "python-application-${version}";
@@ -973,6 +987,24 @@ let
     };
   };
 
+  proboscis = pythonPackages.buildPythonPackage rec {
+    name = "proboscis-1.2.6.0";
+
+    src = pkgs.fetchurl {
+      url = "https://pypi.python.org/packages/source/p/proboscis/proboscis-1.2.6.0.tar.gz";
+      md5 = "e4b36449ef7c18f70b8243f4c8bddbca";
+    };
+
+    propagatedBuildInputs = with pythonPackages; [ nose ];
+    doCheck = false;
+
+    meta = with stdenv.lib; {
+      description = "A Python test framework that extends Python's built-in unittest module and Nose with features from TestNG";
+      homepage = https://github.com/rackspace/python-proboscis;
+      license = licenses.asl20;
+    };
+  };
+
   pyechonest = self.buildPythonPackage rec {
     name = "pyechonest-8.0.2";
 
@@ -3048,6 +3080,36 @@ let
     propagatedBuildInputs = with self; [ gflags iso8601 ipaddr httplib2 google_apputils google_api_python_client ];
   };
 
+  gmusicapi = with pkgs; pythonPackages.buildPythonPackage rec {
+    name = "gmusicapi-4.0.0";
+
+    src = pkgs.fetchurl {
+      url = "https://pypi.python.org/packages/source/g/gmusicapi/gmusicapi-4.0.0.tar.gz";
+      md5 = "12ba66607531978b349c7035c9bab311";
+    };
+
+    propagatedBuildInputs = with pythonPackages; [
+      validictory
+      decorator
+      mutagen
+      protobuf
+      setuptools
+      requests
+      dateutil
+      proboscis
+      mock
+      appdirs
+      oauth2client
+    ];
+    doCheck = false;
+
+    meta = with stdenv.lib; {
+      description = "An unofficial API for Google Play Music";
+      homepage = http://pypi.python.org/pypi/gmusicapi/;
+      license = licenses.bsd3;
+    };
+  };
+
   gnutls = buildPythonPackage rec {
     name = "python-gnutls";
     src = pkgs.fetchurl {
@@ -4028,6 +4090,23 @@ let
     };
   };
 
+  validictory = pythonPackages.buildPythonPackage rec {
+    name = "validictory-1.0.0a2";
+
+    src = pkgs.fetchurl {
+      url = "https://pypi.python.org/packages/source/v/validictory/validictory-1.0.0a2.tar.gz";
+      md5 = "54c206827931cc4ed8a9b1cc78e380c5";
+    };
+
+    propagatedBuildInputs = with pythonPackages; [  ];
+    doCheck = false;
+
+    meta = with stdenv.lib; {
+      description = "Validate dicts against a schema";
+      homepage = http://github.com/sunlightlabs/validictory;
+      license = licenses.mit;
+    };
+  };
 
   venusian = buildPythonPackage rec {
     name = "venusian-1.0a7";
@@ -7424,6 +7503,23 @@ let
     };
   });
 
+  oauth2client = pythonPackages.buildPythonPackage rec {
+    name = "oauth2client-1.4.7";
+
+    src = pkgs.fetchurl {
+      url = "https://pypi.python.org/packages/source/o/oauth2client/oauth2client-1.4.7.tar.gz";
+      md5 = "62747643d5af57e57b09e176eda1c1dd";
+    };
+
+    propagatedBuildInputs = with pythonPackages; [ httplib2 pyasn1 pyasn1-modules rsa ];
+    doCheck = false;
+
+    meta = with stdenv.lib; {
+      description = "A client library for OAuth 2.0";
+      homepage = http://github.com/google/oauth2client/;
+      license = licenses.bsd2;
+    };
+  };
 
   oauthlib = buildPythonPackage rec {
     version = "0.7.2";