Fixed Certificate Generation

[BLamy]

The instructions for running node-opcua's test read as follows:

$ git clone git://github.com/node-opcua/node-opcua.git
$ cd node-opcua
$ npm install
$ npm test

However, Doing that (on a mac) will result in the following error:

          set OPENSSL_CONF=/Users/brett/Projects/node-opcua/node_modules/node-opcua-pki/lib/pki/empty_config.cnf
                  OPENSSL_CONF /Users/brett/Projects/node-opcua/node_modules/node-opcua-pki/lib/pki/empty_config.cnf
                  RANDFILE     /Users/brett/Projects/node-opcua/certificates/PKI/own/private/random.rnd
                  CMD         openssl  ca  -config conf/caconfig.cnf  -startdate 20160718212047Z -enddate 20170718212047Z -batch -out "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem" -in "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem.csr"
                  CWD          /Users/brett/Projects/node-opcua/certificates/CA
        stderr Using configuration from conf/caconfig.cnf
        stderr start date is invalid, it should be YYMMDDHHMMSSZ
        stderr 45289:error:0E06D06C:configuration file routines:NCONF_get_string:no value:/BuildRoot/Library/Caches/com.apple.xbs/Sources/OpenSSL098/OpenSSL098-59.40.2/src/crypto/conf/conf_lib.c:329:group=CA_default name=email_in_dn
 ########################################### OPENSSL ERROR  ###############################
Command failed: "openssl" ca  -config conf/caconfig.cnf  -startdate 20160718212047Z -enddate 20170718212047Z -batch -out "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem" -in "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem.csr"
Using configuration from conf/caconfig.cnf
start date is invalid, it should be YYMMDDHHMMSSZ
45289:error:0E06D06C:configuration file routines:NCONF_get_string:no value:/BuildRoot/Library/Caches/com.apple.xbs/Sources/OpenSSL098/OpenSSL098-59.40.2/src/crypto/conf/conf_lib.c:329:group=CA_default name=email_in_dn

 ########################################### OPENSSL ERROR  ###############################
ERROR  Command failed: "openssl" ca  -config conf/caconfig.cnf  -startdate 20160718212047Z -enddate 20170718212047Z -batch -out "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem" -in "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem.csr"
Using configuration from conf/caconfig.cnf
start date is invalid, it should be YYMMDDHHMMSSZ
45289:error:0E06D06C:configuration file routines:NCONF_get_string:no value:/BuildRoot/Library/Caches/com.apple.xbs/Sources/OpenSSL098/OpenSSL098-59.40.2/src/crypto/conf/conf_lib.c:329:group=CA_default name=email_in_dn

Command failed: "openssl" ca  -config conf/caconfig.cnf  -startdate 20160718212047Z -enddate 20170718212047Z -batch -out "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem" -in "/Users/brett/Projects/node-opcua/certificates/client_cert_1024.pem.csr"
Using configuration from conf/caconfig.cnf
start date is invalid, it should be YYMMDDHHMMSSZ
45289:error:0E06D06C:configuration file routines:NCONF_get_string:no value:/BuildRoot/Library/Caches/com.apple.xbs/Sources/OpenSSL098/OpenSSL098-59.40.2/src/crypto/conf/conf_lib.c:329:group=CA_default name=email_in_dn

This PR formats the date as YYMMDDHHMMSSZ instead of YYYYMMDDHHMMSSZ

[coveralls]

Coverage remained the same at 98.907% when pulling 0825e39 on BLamy:patch-1 into 7d6aeae on node-opcua:master.

[erossignon]

@BLamy , it looks like the openssl version on Mac is outdated ( 0.98) , this is why date are YYMMDDHHMMSSZ instead of YYYYMMDDHHMMSSZ. I would rather not reduce the length of the year but may be add some code to detect that the verison of openssl doesn't meet a required minimum.
Have you tryed to update openssl ?
may be those articles will help:

• http://stackoverflow.com/questions/15185661/update-openssl-on-os-x-with-homebrew
• http://apple.stackexchange.com/questions/126830/how-to-upgrade-openssl-in-os-x

[erossignon]

see also node-opcua/node-opcua#235