add 3.5.0 beta1, remove alpha versions

plugins/python-build/share/python-build/3.5.0a2

@@ -1,3 +0,0 @@
-#require_gcc
-install_package "readline-6.3" "http://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
-install_package "Python-3.5.0a2" "https://www.python.org/ftp/python/3.5.0/Python-3.5.0a2.tgz#8e72209d95f286efb33bf96a6593d475" ldflags_dirs standard verify_py35 ensurepip

plugins/python-build/share/python-build/3.5.0a3

@@ -1,3 +0,0 @@
-#require_gcc
-install_package "readline-6.3" "http://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
-install_package "Python-3.5.0a3" "https://www.python.org/ftp/python/3.5.0/Python-3.5.0a3.tgz#5521bdf9ae9af5b794cd65477bcb02a3" ldflags_dirs standard verify_py35 ensurepip

plugins/python-build/share/python-build/3.5.0a4

@@ -1,3 +0,0 @@
-#require_gcc
-install_package "readline-6.3" "http://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
-install_package "Python-3.5.0a4" "https://www.python.org/ftp/python/3.5.0/Python-3.5.0a4.tgz#34667f07604352a4a1ef4651dcb7f870" ldflags_dirs standard verify_py35 ensurepip

plugins/python-build/share/python-build/3.5.0a1 → plugins/python-build/share/python-build/3.5.0b1

@@ -1,3 +1,3 @@
 #require_gcc
 install_package "readline-6.3" "http://ftpmirror.gnu.org/readline/readline-6.3.tar.gz#56ba6071b9462f980c5a72ab0023893b65ba6debb4eeb475d7a563dc65cafd43" standard --if has_broken_mac_readline
-install_package "Python-3.5.0a1" "https://www.python.org/ftp/python/3.5.0/Python-3.5.0a1.tgz#f1ea32ce88ffff8787ea31302e00b05a" ldflags_dirs standard verify_py35 ensurepip
+install_package "Python-3.5.0b1" "https://www.python.org/ftp/python/3.5.0/Python-3.5.0b1.tgz#1a4f57ad2ec0dd9b17703e13b46b96256b55b28d9e6529005e72f3d660e3f8a1" ldflags_dirs standard verify_py35 ensurepip