py-tvdb: remove 'dev' from version, add py37

- previous 2.0-dev version string causes py-tvnamer not to realize the
    version is sufficient

python/py-tvdb/Portfile

@@ -18,11 +18,17 @@ long_description    ${description}
 checksums           rmd160  e36c246fdd0ad5f4955caec3d1374c1983490562 \
                     sha256  15849f43fb29bb34f12ca539572720c256e35f93cb72664be13076a6bfe227f1
 
-python.versions     27 34 35 36
+python.versions     27 34 35 36 37
 
 if {$subport ne $name} {
-    depends_build   port:py${python.version}-setuptools
+    depends_build-append \
+                    port:py${python.version}-setuptools
 
-    depends_lib     port:py${python.version}-requests \
+    depends_lib-append \
+                    port:py${python.version}-requests \
                     port:py${python.version}-requests-cache
+
+    post-extract {
+        reinplace "s|'${version}-dev'|'${version}'|g" ${worksrcpath}/setup.py
+    }
 }